Question

sin10*sin50*sin70=?

Answer 1

sin 10 * sin(60-10) * sin(60+10)

Answer 2

sin 10 * (sin^2 60 - sin^2 10)

Answer 3

3/4 *sin10 - sin^3 10

Answer 4

i am stuck from here

Answer 5

emm !
sin(60-10) * sin(60+10) is not equal (sin^2 60 - sin^2 10)

Answer 6

=cos20 cos 40 cos 80
then use sin 40 = 2 sin 20 cos 20

Answer 7

sin(60-10) * sin(60+10) is not equal (sin^2 60 - sin^2 10)??????/ why

Answer 8

because its not of the form (a+b)(a-b)

Answer 9

there is difference between (a+b)(a-b) and sin(a+b)sin(a-b)

Answer 10

=cos20 cos 40 cos 80
then use sin 40 = 2 sin 20 cos 20
and sin 80 = 2 sin 40 cos 40
substitute the values of cos20 and cos 40

Answer 11

u will also need sin 160=2 sin 80 cos 80
and sin 160=sin 20
in the end everything will cancel and u will get 1/8

Answer 12

lol...@hartnn i too got the same answer using that formula

Answer 13

@mukushla @hartnn

Answer 14

sin 70 = cos (90-70)=cos 20
similarly for sin10 and sin 50

Answer 15

so @Yahoo! whats the problem?

Answer 16

sin(60-10) * sin(60+10) is not equal (sin^2 60 - sin^2 10)?

Answer 17

yup,those are not equal.

Answer 18

ok..thxx