Question

The real numbers a and b are such that the discriminant of the quadratic [f(x) = ax^2 - bx - 16]is less than or equal to 0. Find the largest possible value of 4a - b.

Answer 1

The answer is 4.

Step-by-step explanation:

`f(x)=a*x^(2) -b*x-16\leq 0\\a*x^(2) -b*x\leq 16\\(a*x-b)*x\leq 16`

When we put 4 instead of x, the equation will be:

`(4a-b)*4\leq 16\\(4a-b)\leq 4`

Find the largest possible value of 4a - b is 4