Hey guys, here's a problem I'm stuck on:

The lifetime of X (years) has pdf:

f(x) = 2x/(theta²) *e^ -(x/theta)² , when... 0<x<infinity

If P(X>5) = 0.01, determine theta.

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So I thought, P(x>5) = 1-P(x<5)

so, 1- integral (from 0-->5) f(x) = 0.01

Is this the right logic? If so, the problem becomes evaluating that integral.

Can someone help me? It's been two years since Calculus, and I'd appreciate it.