Question

The roots of
`10x^2-14x+k` are sin a and cos a for some real value of a. Compute k.

Answer 1

10

Explanation:

10x²-14x+k = 0

x1 = sin a

x2= cos a

x1+x2 ≤ 2

x1. x2 ≤ 1 => k/10 ≤ 1

k ≤ 10

so the value of k should be 10