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

sin(3x) = 3cos^{2}x.sin(x)-sin^{3}x. Please give me proof for above formula.

sin(3x) = 3cos^{2}x.sin(x)-sin^{3}x.
Please give me proof for above formula.

Grade:12

3 Answers

Raghuvaran varan Chandragiri
37 Points
8 years ago

sin(2x+x)=sin2x.cosx+cos2x.sinx

             =2sinxcosx.cosx+(-2sin^2x)sinx

             =2sinxcos^2+sinx-2sin^3x

            =sinx(2cos^2x+1)-2sin^3x

=sinx(2-2sin^2x+1)-2sin^3x

           =2sinx-2sin^3x+sinx-2sin^3x

                                            = 3sinx-4sin^3x

badapalli Kurmarao
31 Points
8 years ago

sin(2x+x)=sin2x.cosx+cos2x.sinx

 =2sinxcosx.cosx+(-2sin^2x)sinx

=2sinxcos^2+sinx-2sin^3x

 =sinx(2cos^2x+1)-2sin^3x

=sinx(2-2sin^2x+1)-2sin^3x

 =2sinx-2sin^3x+sinx-2sin^3x

 = 3sinx-4sin^3x

 

prasanth battula
37 Points
8 years ago

thank you,you missed putting 1 in the second step in your answer

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