Question

F(x)=x^2-3x-15 what’s the root

Answer 1

There are two roots:

(3 + √69)/2 and (3 - √69)/2

Explanation:

Use the quadratic equation to solve this...

x = [-b ± √(b² - 4ac)]/(2a)

Here, a = 1, b = -3, and c = -15, plug them in and simplify

x =([-(-3) ± √[(-3)² - 4(1)(-15)])/[2(1)]

x = (3 ± √[9 - (-60)])/2

x = (3 ± √69)/2

so

x = (3 + √69)/2 and x = (3 - √69)/2