Question

cos 21°÷sin69°-sin40°÷cos50°
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Answer 1

CHECK THE ATTACHMENT !!

Answer 2

Step-by-step explanation:

ANSWER:-

We know that

Sin theta = Cos ( 90- theta)

So is the inverse ie

Cos theta = Sin ( 90- theta)

• So we can write cos 21° as Sin 69°

And also

• we can write sin 40° as Cos 50°

If we replace the values we get

Sin 21°/ Sin 21° - cos 50°/ cos 50°

= 1-1

So the answer is ZERO.

SOME IDENTITIES

• Sin0 = cos(90-0)
• Cos0= sin(90-0)
• Tan0 = cot(90-0)
• Cot0 = tan(90-0)
• Sec0 = cosec(90-0)
• Cosec = sec(90-0)
• These all are complementary of each other
• Where 0 = theta
• sin is Inverse of cosec
• cos is Inverse of sec
• tan is Inverse of cot
• And vice versa are also correct