Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

What is the formula for cos3a.and also tell about the method to get it

What is the formula for cos3a.and also tell about the method to get it

Grade:9

1 Answers

Nikhil Upadhyay
171 Points
6 years ago
cos3a=4cos3a-3cosa.you can get it by writing it in the form cos(a+b) as cos(2a+a)
=cos2a*cosa-sin2a*sina
=(2cos2a-1)cosa-2sinacosasina
=(2cos2a-1)cosa-2cosa(1-sin2a)
=2cos3a-cosa-2cosa+2cos3a
=4cos3a-3cosa.PLZ approve

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free