Question

Sin 30 = cos x then find x =
​

Answer 1

Given :

Sin30 = cos x

What to find out = value of x?

Solution :

Sin30 = cos x

As sin30 = 1/2

So, 1/2= cosx

As 1/2 = cos60

So, cos 60 = cos x

X= 60 degree. Answer.

Some important trigonometry Formulae :

• Sec θ . Cos θ =1

• Cosec θ . Sin θ =1

• Cot θ . Tan θ =1

• Tan θ = sin θ/cos θ

• Cot θ = cos θ/sin θ

• Sin θ = tan θ/cos θ

• Cos θ = sin θ/tan θ

• Sec θ = tan θ/sin θ

• Cosec θ = cos θ/tan θ

• Sin (90°-θ) = Cos θ

• Cos (90°-θ) = Sin θ

• Tan (90°-θ) = Cot θ

• Cot (90°-θ) = Tan θ

• Sec (90°-θ) = Cosec θ

• Cosec (90°-θ) = Sec θ