Question #04cb2

1 Answer
Apr 7, 2017

I hope that this helps.

Explanation:

Prove: #(sin(x)-cos(x))/(sin(x)+cos(x)) = (tan(x)-1)/(tan(x)+1)#

Multiply the left side by 1 in the form of #(1/cos(x))/(1/cos(x))#

#(sin(x)-cos(x))/(sin(x)+cos(x))(1/cos(x))/(1/cos(x)) = (tan(x)-1)/(tan(x)+1)#

Distribute #1/cos(x)# through the numerator and the denominator:

#(sin(x)/cos(x)-cos(x)/cos(x))/(sin(x)/cos(x)+cos(x)/cos(x)) = (tan(x)-1)/(tan(x)+1)#

Substitute #tan(x)# for #sin(x)/cos(x)# and 1 for #cos(x)/cos(x)#

#(tan(x)-1)/(tan(x)+1) = (tan(x)-1)/(tan(x)+1)#

Q.E.D.