Question

find x if 2cos3x-sin90+cos 90=1
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Answer 1

Answer:

xsin(90 -A)cot(90-A)=cos(90- A) x.cosA.tanA=sinA x=1. Because if you take cosA to right side then it will convert into tanA by dividing with sinA so ,now ... And You get x= 1.

Answer 2

Answer:

substitute values for cos90 &sin 90 which is 0&1 rsply..

2cos3x=2

cos3x=1

3x=0

x=0 or2pie