
David L. answered 04/30/20
Very Exerpienced Precalculus Tutor and Teacher
The Mean Value Theorem for Integrals states that if f(x) is a continuous function on the closed interval [a, b], then there exists a number c in that interval such that:
∫ f(x)dx = f(c)*(b-a) (The integral is a definite integral from a lower value a to an upper value b)
Since f(x) = 2 - x2 is continuous on the interval [0, √2] we can apply the Mean Value Theorem for Integrals.
F(x) = ∫ f(x)dx = 2x - x3/3
Evaluate the integral at x=√2 and then at x=0, then take the difference
F(√2) = 2√2 - 2√2/3 = 4√2/3
F(0) = 0
Therefore the integral is equal to F(√2) - F(0) = 4√2/3
We plug this into the MVT for integrals and then solve for c
4√2/3 = (√2 - 0)*f(c)
4√2/3 = √2*(2-c2)
4/3 = 2-c2
c2 = 2/3
c = √(2/3)