# calculus

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So I am suppose to evaulate this problem y=tan^4(2x) and I am confused.

my friend did this : 3 tan ^4 (2x) d sec^ 2x (2x)= 6 tan ^4 (2x) d sec^2 (2x)
She says it's right but what confuses me is she deriving the 4 and made it a three? I did the problem like this:
tan^4 (2x)= 4 tan^3 (2x) d sec ^2 (2x)(2x)= 8 tan^3 (2x) d sec^2 (2x)

Can anyone explain this to me?

• calculus -

Go on :

wolframalpha dot com

Whe page be open in rectangle type :

derivative tan^4(2x)

then click option =

After few seconds when you see result click option :

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