I have the question evaluate the following : cos(-pi/12)(adsbygoogle = window.adsbygoogle || []).push({});

I rewrote this to be -15 degrees = 345 degrees.

I think Im supposed to use the sum and difference formula or special triangle, so I wrote

cos(30degrees-45degrees)= cos 30 cos 45 - sin 30 sin 45

my answer turned out to be 0.5124 but it says the correct answer is 0.9659 what did I do wrong?

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# Homework Help: How do I evaluate this properly? Trig

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