Q4 of 87 Page 34

Determine whether the values given against each of the quadratic equation are the roots of the equation.

(1) x2 + 4x – 5 = 0, x = 1, -1


(2)

1)


Put


⇒


⇒


Put


⇒


⇒


∴ is a root of the equation and is not a root of the equation.


2)


Put , ⇒ ⇒


Put , ⇒


∴ is not root of the equation and is a root of the equation.


More from this chapter

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2

Decide which of the following are quadratic equations.

(1) x2 + 5x – 2 = 0


(2) y2 = 5y - 10


(3)


(4)


(5) (m + 2)(m–5) = 0


(6) m3 + 3m2 – 2 = 3 m3

3

Write the following equations in the form ax2 + bx + c = 0, then write the values of a, b, c for each equation.

(1) 2y = 10 – y2


(2) (x-1)2 = 2x + 3


(3) x2 + 5x = - (3-x)


(4) 3m2 = 2m2 - 9


(5) P(3 + 6p) = - 5


(6) x2 – 9 = 13

 5

Find k if x = 3 is a root of equation kx2 – 10x + 3 = 0.

 6

One of the roots of equation 5m2 + 2m + k = 0 is Complete the following activity to find the value of 'k'.