Question

证明[1/cos(-α)+cos(180°+ α )]/[1/sin(540°+α)+sin(360°-α)]=tan^

Answer 1

证明：

左边=[1/cos(-α)+cos(180°+ α )]/[1/sin(540°+α)-sin(360°-α)]

=[1/cos(α)-cos( α )]/[1/sin(180°+α)+sin(α)]

=[1/cosα-cos α]/[1/（-sinα）+sinα]

=[cos² αsinα-sina]/[cosα-sin²αcosa]

=[sina/cosa][cos² α-1]/[1-sin²α]

=tana[sin²a/cos²a)

=tan³a

=右边