Question

prove that 1+cosA/1-cosA - 1-cosA/1+cosA = 4cotACosecA

Answer 1

Answer:

Step-by-step explanation:

(1+cosA)/(1-cosA) -( 1-cosA)/(1+cosA)

=【(1+cosA)²+( 1-cosA)²】/（1-cos²A）

=4cosA/sin²A

=4cosA/(sinA*sinA)

=4(cosA/sinA) * (1/sinA)

=4cotA * cscA

Answer 2

(1+cosA)/(1-cosA) -( 1-cosA)/(1+cosA)

=【(1+cosA)²+( 1-cosA)²】/（1-cos²A）

=4cosA/sin²A

=4cosA/(sinA*sinA)

=4(cosA/sinA) * (1/sinA)

=4cotA * cscA