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AP Calculus Verifying a Solution to a Differential Equation Trig Function (question)

why did the -sin^2(x) change into -1 + cos^2x?

Re: AP Calculus Verifying a Solution to a Differential Equation Trig Function (questi

$\displaystyle \sin^{2}x+\cos^{2}x = 1.$

Re: AP Calculus Verifying a Solution to a Differential Equation Trig Function (questi

Re: AP Calculus Verifying a Solution to a Differential Equation Trig Function (questi

Quote:

Originally Posted by

**asilvester635** i don't get it

Do you get that if $\displaystyle s^2+c^2=1$ then $\displaystyle -s^2=-1+c^2~?$

Re: AP Calculus Verifying a Solution to a Differential Equation Trig Function (questi

It's a basic trig identity that by now, (judging by what you are doing), you should be familiar with.

It can be rewritten as

$\displaystyle -\sin^{2}x = -1 +\cos^{2}x.$

Re: AP Calculus Verifying a Solution to a Differential Equation Trig Function (questi

yah i forgot its a trig identity.. thanks anyways