How do you verify the identity cosxcotx = cscx - sinx?

2 Answers
Mar 17, 2018

All the identities you will need:
cotx= cosx/sinx
cos^2x= 1-sin^2x
1/sinx= cscx

Starting:
cosxcotx= cscx-sinx

Apply number 1 on the list:

cosx*cosx/sinx= cscx-sinx

Simplify:

cos^2x/sinx= cscx-sinx

Apply number 2 on the list:

(1-sin^2x)/sinx= cscx-sinx

Split the numerator:

1/sinx-sin^2x/sinx= cscx-sinx

Apply number 3 on the list:

cscx-sinx=cscx-sinx

Mar 17, 2018

Kindly go through a Proof in the Explanation.

Explanation:

We have, cosxcotx+sinx,

=cosx*cosx/sinx+sinx,

=(cos^2x+sin^2x)/sinx,

=1/sinx,

:. cosxcotx+sinx=cscx.

rArr cosxcotx=cscx-sinx, as desired!