Implemented Components
Check whether the following are quadratic equations :
(iii)
(iv)
1. The area of a rectangular plot is 528 m2 . The length of the plot (in metres) is one more than twice its breadth. We need to find the length and breadth of the plot.
- Now, Let x be the breadth of the rectangular plot in meters.
- The length y is given to be one more than twice the breadth (Step 1)
- Area=length×breadth (Step 2)
- Substituting given values (Step 3)
- Now, simplify and expand the equation: (Step 4)
- Rearranging the equation into standard form
- The equation is
2 b 2 + b − 528 = 0
2. The product of two consecutive positive integers is 306. We need to find the integers
(ii)
- Now, Let one integer be x.
- The other integer would be x+1.
- Writing the equation(Step 1)
- Simplifying the equation (Step 2)
- Rearranging the equation into standard form (Step 3)
- The equation is
x 2 + x − 306 = 0
3.Rohan’s mother is 26 years older than him. The product of their ages (in years) 3 years from now will be 360. We would like to find Rohan’s present age.
(iii)
- Now, Let Rohan’s current age be x years.
- Rohan’s mother’s current age will be x+26 years.
- In 3 years, Rohan will be x+3 years and his mother will be x+29 years.
- Writing the equation (Step 1)
- Now, simplify and expand the equation: (Step 2)
- Combine like terms (Step 3)
- Rearranging the equation into standard form (Step 4)
- The equation is
x 2 + 32 x − 273 = 0
4.A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, then it would have taken 3 hours more to cover the same distance. We need to find the speed of the train.
- Now, Let initial speed be x.
- Speed if it had been 8 kmph less would be (x-8). (Step 1)
- Writing the equation (Step 2)
- Clear the fractions by multiplying through by 𝑥(𝑥−8): (Step 3)
- Simplify the equation: (Step 4)
- Combine like terms and rearrange the equation into standard form (Step 4)
- The equation is
x 2 − 8 x − 1280 = 0
(i)
- To find roots of the given equation:
- Identify the coefficients:
- a=1 (coefficient of
)x 2 - 𝑏=−3(coefficient of
x ) - 𝑐=−10(constant term)
- Find two numbers that multiply to 𝑎𝑐 and add to 𝑏: (Step 2)
- Rewrite the middle term using these numbers: (Step 3)
- Factor by grouping:: (Step 4)
- Factor out the common binomial factor:(Step 4)
- Set each factor equal to zero to find the roots:
- The roots are:
,
(ii)
- To find roots of the given equation:
- Identify the coefficients:
- a=2 (coefficient of
)x 2 - 𝑏=1(coefficient of
x ) - 𝑐=−6(constant term)
- Find two numbers that multiply to 𝑎𝑐 and add to 𝑏: (Step 2)
- Rewrite the middle term using these numbers: (Step 3)
- Factor by grouping:: (Step 4)
- Factor out the common binomial factor:(Step 5)
- Set each factor equal to zero to find the roots:
- The roots are:
,
(iii)
- To find roots of the given equation:
- Identify the coefficients:
- a=2^1/2 (coefficient of
)x 2 - 𝑏=7(coefficient of
x ) - 𝑐=5*(2^1/2)(constant term)
- Find two numbers that multiply to 𝑎𝑐 and add to 𝑏: (Step 2)
- Rewrite the middle term using these numbers: (Step 3)
- Factor by grouping: (Step 4)
- Factor out the common binomial factor:(Step 5)
- Set each factor equal to zero to find the roots:
- The roots are:
,
(iv)
- To find roots of the given equation:
- Identify the coefficients:
- a=2(coefficient of
)x 2 - 𝑏=-1(coefficient of
x ) - 𝑐=1/8(constant term)
- Multply the whole equation by 8 and find two numbers that multiply to 𝑎𝑐 and add to 𝑏: (Step 2)
- Rewrite the middle term using these numbers: (Step 3)
- Factor by grouping: (Step 4)
- Factor out the common binomial factor:(Step 5)
- Set each factor equal to zero to find the roots:
- The roots are:
,
(v)
- To find roots of the given equation:
- Identify the coefficients:
- a=100(coefficient of
)x 2 - 𝑏=-20(coefficient of
x ) - 𝑐=1(constant term)
- Rewrite the middle term using these numbers: (Step 3)
- Factor by grouping: (Step 4)
- Factor out the common binomial factor:(Step 5)
- Set each factor equal to zero to find the roots:
- The roots are:
,
(i) John and Jivanti together have 45 marbles. Both of them lost 5 marbles each, and the product of the number of marbles they now have is 124. We would like to find out how many marbles they had to start with.
- Now, Let x be the no.of marbles John had.
- The length
is given to be no.of marbles Jivanti had. - No.of marbles John had left after he lost 5 marbles=x-5
- No.of marbles left with Jivanti when she lost 5 marbles=40-x
- the product of the no.of marbles they have now is
=124 - Rearranging the equation into standard form
- The equation is
x 2 − 45 x + 324 = 0
ii.A cottage industry produces a certain number of toys in a day. The cost of production of each toy (in rupees) was found to be 55 minus the number of toys produced in a day. On a particular day, the total cost of production was ` 750. We would like to find out the number of toys produced on that day.
- Now, Let x be the no.of toys produced on that day.
- The cost of production (in rupees) of each toy that day is
. - Total cost of production that day=
=750 - Rearranging the equation into standard form
- The equation is
(iii)Find two numbers whose sum is 27 and product is 182* Now, Let x be the no.of toys produced on that day.
- Let the two numbers be x and y.
- The sum is given by
x + y = 27 - The product is given by xy=182
y = 27 − x - Substitute y in the product equation.
x 27 − x = 182 27 x − x 2 = 182 - The new equation is
- To find roots of the given equation:
- Identify the coefficients:
- a=1(coefficient of
)x 2 - 𝑏=-27(coefficient of
x ) - 𝑐=182(constant term)
- Rewrite the middle term using these numbers: (Step 3)
- Factor by grouping: (Step 4)
- Factor out the common binomial factor:(Step 5)
- Set each factor equal to zero to find the roots:
- The roots are:
,
- Find two consecutive positive integers, sum of whose squares is 365. The two integers are
and .
5.** The altitude of a right triangle is 7 cm less than its base. If the hypotenuse is 13 cm, find the other two sides.** The other two sides are
- **A cottage industry produces a certain number of pottery articles in a day. It was observed on a particular day that the cost of production of each article (in rupees) was 3 more than twice the number of articles produced on that day. If the total cost of production on that day was
90 , find the number of articles produced and the cost of each article. ∗ The number of articles produced is 6 and cost of each article is rupee`.
To find the values of 𝑘k for the quadratic equation 2x^2 + kx + 3 = 0 so that it has two equal roots, we need to make its discriminant Delta equal to zero.
The discriminant (\Delta) of a quadratic equation ax^2 + bx + c = 0 is given by:
- Delta = b^2 - 4ac
- For the equation
2 + kx + 3 = 0:x 2 - a = 2 (coefficient of
)x 2 - b = k (coefficient of x)
- c = 3 (constant term)
- Substitute these values into the discriminant formula:
- Delta =
- 4(2)(3)k 2 - For the equation to have two equal roots, the discriminant must be equal to zero:
- k^2 - 24 = 0
- Now, solve for k:
= 24k 2 - k = pm \sqrt{24}
- k = pm 2\sqrt{6}
- So, the values of k for the equation 2x^2 + kx + 3 = 0 to have two equal roots are k = 2\sqrt{6} and k = -2\sqrt{6}.
To determine if it is possible to design a rectangular mango grove whose length is twice its breadth, and the area is 800 m², we need to solve the following problem:
- Let the breadth of the rectangle be b meters.
- Since the length is twice the breadth, the length will be 2b meters.
- The area of the rectangle is given by the product of its length and breadth.
- Set up the equation for the area:
- Area = length × breadth
- 800 = 2b × b
- Simplify the equation:
- 800 = 2b^2
- Divide both sides by 2:
- 400 = b^2
- Solve for b by taking the square root of both sides:
- b = sqrt(400)
- b =
- So, the breadth is 20 meters.
- Since the length is twice the breadth, the length will be:
- length = 2b
- length = 2(20)
- length =
- So, the length is 40 meters.
- Therefore, it is possible to design a rectangular mango grove with the given conditions. The dimensions are:
- length =
meters - breadth =
meters
To determine if it is possible to design a rectangular park with a perimeter of 80 meters and an area of 400 square meters, we need to solve the following problem:
Let the length of the rectangle be
- Let the breadth of the rectangle be b meters.
- The perimeter of the rectangle is given by:
- Perimeter = 2(l + b)
- 80 = 2(l + b)
- Simplify the equation:
- l + b = 40
- The area of the rectangle is given by:
- Area = l * b
- 400 = l * b
- We now have a system of two equations to solve:
- l + b = 40
- l * b = 400
- Express b in terms of l using the first equation:
- b = 40 - l
- Substitute b in the second equation:
- l * (40 - l) = 400
- 40l -
= 400l 2 - Rewrite the equation as a standard quadratic equation:
- l^2 - 40l + 400 = 0
- Solve the quadratic equation using the quadratic formula l =
:− b ± b 2 − 4 ac 2 a - Identify the coefficients:
- a = 1, b = -40, c = 400
- Calculate the discriminant Delta:
- Delta =
- 4acb 2 - Delta =
- 4(1)(400)− 40 2 - Delta = 1600 - 1600
- Delta =
- Since the discriminant is zero (Delta = 0), the quadratic equation has exactly one real root:
- l =
− − 40 ± 0 2 · 1 - l =
40 2 - l =
- Substitute l =
back into the equation b = 40 - l to find b: - b = 40 - 20
- b =
- So, the length is
meters and the breadth is meters. - Therefore, it is possible to design a rectangular park with the given conditions. The dimensions are:
- length = 20 meters, breadth = 20 meters