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sin s + sin t = 2sin((s + t)/2)cos((s – t)/2)
sin75 + sin15 = 2sin((75 + 15)/2)cos((75 - 15)/2)
sin75 + sin15 = 2sin(90/2)cos(60/2)
sin75 + sin15 = 2sin45cos30
sin75 + sin15 = 2(1/2)√2(1/2)√3
sin75 + sin15 = (1/2)√6

2007-06-10 19:55:29 · answer #1 · answered by Helmut 7 · 0 0

Sin 75 Sin 15

2016-12-10 13:21:19 · answer #2 · answered by ? 4 · 0 0

ASSUMING THE VALUES ARE IN DEGREES:

SIN(75°) + SIN(15°)

CAN BE SIMPLIFIED TO:

(√6/4 + √2/4) + (√6/4 - √2/4)

THEREFORE, THE ANSWER IS:

√6/2

OR

1.224744871

2007-06-10 20:18:37 · answer #3 · answered by Rey Arson II 3 · 0 0

you employ the a million/2-perspective formula: sin(theta/2) = +/- sqrt((a million-cos(theta))/2). 30 stages is between the ordinary angles that maximum trig instructors anticipate you to memorize; its cosine is sqrt(3)/2. So sin(15) = sin(30/2) = +/- sqrt(a million-sqrt(3)/2)/2) = +/- sqrt(a million/2 - sqrt(3)/4). To get the sign, you basically ought to apply some easy experience. 15 stages is interior the 1st quadrant of the unit circle, so its sine and cosine ought to the two be useful. provided that a sq. root is often useful, all of us understand that sin(15) = sqrt(a million/2 - sqrt(3)/4). i'm going to wager there is a few thank you to simplify that, yet i won't be in a position to think of what it must be.

2016-12-12 17:42:12 · answer #4 · answered by ? 4 · 0 0

sqrt=square root

sin(75)+sin(15)
=sin(45+30)+sin(60-45)
=sin(45)cos(30)+cos(45)sin(30)+
sin60cos45-cos60sin45
=(1/sqrt 2)(sqrt 3/2)+(1/sqrt 2)(1/2)+
(sqrt 3/2)(1/sqrt 2)-(1/2)(1/sqrt 2)
=(1/sqrt 2)[sqrt 3/2 +1/2 +sqrt 3/2 -1/2]
=(1/sqrt 2)[2sqrt 3/2]
=sqrt 3 /sqrt 2
=sqrt (3/2) #

2007-06-10 20:05:26 · answer #5 · answered by jackleynpoll 3 · 0 0

use the formula sinC+sinD=2sin{(C+D)/2}*cos{(C+D)/2},simplify and then look into the sine values chart to get exact decimal values.

2007-06-10 19:48:35 · answer #6 · answered by Anonymous · 0 1

sinA+sinB=2sin(A+B)/2 cos(C-D)/2
=2sin45*cos30

now look fr these values...

2007-06-10 19:59:51 · answer #7 · answered by himz 1 · 0 0

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