Q5 of 47 Page 1

Find the roots of the quadratic equation √2x2 + 7x + 5√2 = 0.

Here, on comparing with general equation ax 2 + bx + c = 0, we get

a = √2


b = 7


c = 5√2


Now, Discriminant = D = (b2 – 4ac)


∴ D = [49 – (4 × √2 × 5√2)]


= [49 - 20]


= 9


Therefore roots of the equation are given by:


x = (-b √D)/2a


∴ x = (-7 (√9))/2√2


= [(-7-3)/2√2] or [(-7 + 3)/2√2]


= -10/2√2 or -4/2√2


= -5/√2 or -√2 .


Thus the roots of the equation are: 5/√2 and √2.


More from this chapter

All 47 →
3

A number is chosen at random from the numbers −3,−2,−1,0,1,2,3. What will be the probability that square of this number is less than or equal to 1?

 4

If the distance between the points (4, k) and (1, 0) is 5, then what can be the possible values of k?

 6

Find how many integers between 200 and 500 are divisible by 8.

 7

Prove that tangents drawn at the ends of a diameter of a circle are parallel to each other.