How many x-intercepts does the function f(x)=-2x^2+8x

What’s the answer ? use the picture to see the problem

Ming says that 0.24 > 1/4 because 0.24= 2/4. which best explains mings error

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.