Question

1.the value of sin30°.sin45°.cosec45°.cos30°=?

2.if 1-tan square 60 / 1+ tan square 60 = cos X then the value of X is = ?

please help me friends
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Answer 1

Answer:

1) $\frac{ \sqrt{3} }{4}$

2) -1/2

Answer 2

here u should know

sin60 = √3/2

sin30 sin45 cosec45 cos30

as cosec45 = 1/sin45

sin 30 sin45 × 1/sin45. × cos30

sin30 cos 30

Sin2x = 2 sinx cos x

sin60/2 = sin30 cos 30,

So sin60/2

√3/4

2) cos2x = 1- tan^2x)/1+ tan^2x

So

1- tan^260)/1+tan^260. = cos x

Cos 120 = cos x

x= 2npie+- 120 ( in 1st and 4 th quadrant)

1st = 2npie+ 120

4 th = 2npie -120