Question

sin A = cos 45°, then the value of 3 tan4 A - 4 tan 45° will be ___ .​

Answer 1

Answer:

if sinA=cos45

then sinA=1/√2

so A=45

so 4A=180

tan180=tan(180-0),by rule of coterminal angle

=tan0=0

so 3tan180=0 (1)

4tan45=4×1=4(2)

so 0-4=-4

hence answer is -4 :)