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Algebra Difficulty 1.7 Junior Find the answer

Let the function f(x)=x2sinx+2f(x) = x^2 \sin x + 2. If f(a)=15f(a) = 15, then f(a)=11f(-a) = \boxed{-11}.

A number or a short expression. Spacing and $ signs are ignored.

Solution

Given that f(a)+f(a)=4f(a) + f(-a) = 4, therefore f(a)=415=11f(-a) = 4 - 15 = -11.

Hence, the answer is 11\boxed{-11}.

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Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.