# maths...

posted by
**Aoi**
.

Differentiate ln [x+√(x^2+1)] with respect to x

hence evaluate limit 0 to 1

∫ 1/√(x^2+1) dx

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Use the identity cos3x=4cos^3x-3cosx,

find ∫cos^3x dx

* Is there a printing error in the question? the limit is from pi/2 to pi/2?!