Question

Sin 70° ÷ cos 20° + cosec 20° ÷ sec 70° - 2 cos 70°× cosec 20° = 0 prove.

Answer 1

Sin70/cos 20+cosec20/sec70

-2cos70*cosec20

=Sin(90-70)/cos20 + cosec20(90-20)/sec70 - 2 cos70 * cosec (90-20)

=cos20/cos20 + sec 70 / sec 70

-2*cos70*sec70

=1+1-2cos70*1/cos70

=2-2*1

=2-2=0

Hence proved

Answer 2

Answer:

Step-by-step explanation:

Sin70/cos(90-20) + cosec20/sec(90-70) - 2*1/sec70 * cosec20

:. Sin70/sin70 + cosec20/cosec20 -2*1/sec(90-70) * cosec20

= 1+1-2*1/cosec20 * cosec20

=2-2

=0