MathDB
Today's calculation of Integral 531

Source: 1967 Keio University entrance exam/Medical

January 19, 2010
calculusintegrationfunctiontrigonometrygeometryrectanglecalculus computations

Problem Statement

(1) Let f(x) f(x) be a continuous function defined on [a, b] [a,\ b], it is known that there exists some c c such that \int_a^b f(x)\ dx \equal{} (b \minus{} a)f(c)\ (a < c < b) Explain the fact by using graph. Note that you don't need to prove the statement. (2) Let f(x) \equal{} a_0 \plus{} a_1x \plus{} a_2x^2 \plus{} \cdots\cdots \plus{} a_nx^n, Prove that there exists θ \theta such that f(\sin \theta) \equal{} a_0 \plus{} \frac {a_1}{2} \plus{} \frac {a_3}{3} \plus{} \cdots\cdots \plus{} \frac {a_n}{n \plus{} 1},\ 0 < \theta < \frac {\pi}{2}.