How to solve 1+cos2X/cotx?
#(1+cos2X)/cotX# I got 2cosxsinx but that doesn't sound right please help!
1 Answer
Explanation:
It is right
We will use
-
#cot(x)=cos(x)/sin(x)# -
#cos(2x)=2cos^2(x)-1# *
Then
Which also can be expressed as
*
A little note why
It can be shown from the trigonometric addiction formulas,
here we use:
Several good proof of the trigonometric addiction formulas are available on the internet
A good intuition is given by the diagram:
And now the working out
We have the trigonometric formula
Substitute
Use
Which was what we wanted to show