Question

sin 660 degree × tan ( - 1050 ) degree × sec 420 degree =? degree ​

Answer 1

Answer:

sin(−660°)tan(1050°)sec(−420°)

=

cos(225°)cosec(315°)cos(510°)

−sin(660°)tan(1050°)sec(−420°)

=

cos(×180

∘

+45°)cosec(2×180

∘

−45°)cos(3×180

∘

−30°)

−sin(4×180

∘

−60°)tan(6×180

∘

−30°)sec(2×180

∘

+60°)

=

cos(π+45°)cosec(2π−45°)cos(3π−30°)

−sin(4π−60°)tan(6π−30°)sec(2π+60°)

=

−cos45°(−cosec45°)(−cos30°)

sin60°(−tan30°)sec60°

=

2

1

×−

2

×−

2

3

2

3

×(

3

−1

)×2

=

3

2

Hence, the answer is

3

2

.