use the given information to find the exact value find sin(A-B) using the sine difference identity cos A= 1/3,0
help me plz
help me plz
Trivial. Just use the sin(A-B) = sinAcosB - sinBCosA formula. You can work out sin(A) from cos(A) (and vice versa) using cos^2(A) + sin^2(A) = 1, which implies sin(A) = +/- sqrt(1-cos^2(A). Use bounds on where A and B are to decide whether each is the positive or negative root.
i really dont get this plz explain me more in a board
No, sorry. I gave you everything you nee.d Now do your own homework. <3
plz help me ranga sir plz
sin(A-B) = sinAcosB - sinBCosA cosA = 1/3 sinB = -1/2 sin(A-B) = sinAcosB - sinBCosA = sin(A-B) = sinAcosB - (-1/2)(1/3) = sinAcosB + 1/6 |dw:1384482360049:dw| Find sinB and cosA from the diagram and substitute.
how do i substitute sir
First find the length of the missing side in the two triangles marked with a question mark. That is, What is PQ in the first triangle and SB in the second triangle?
i dont no how to do that
You should get the basics first before attempting this problem. The figure shows right triangles. AQ^2 + PQ^2 = AP^2 1^2 + PQ^2 = 3^2 Find PQ. (This is the same as using sin^2A + cos^2A = 1. But I showed you the triangle so you can know what sine and cosine represents in a triangle).
2^3
1^2 + PQ^2 = 3^2 1 + PQ^2 = 9 PQ^2 = 9 - 1 = 8 PQ = sqrt(8) = sqrt(4*2) = 2sqrt(2) sin(A) = opposite / hypotenuse = PQ / AP = 2sqrt(2) / 3. This is what you will substitute for sin(A). Use the second triangle to find cos(B) in a similar way.
hmm i got for the pother one sqyrt (2)/2
is it right
hello sir
sqrt(3)/2
yes. And since B is in the fourth quadrant cos(B) is positive. sin(A-B) = sinAcosB + 1/6 sin(A) = 2sqrt(2) / 3 cos(B) = sqrt(3)/2 Substitute into sin(A-B) = sinAcosB + 1/6
so my answer is 2sqrt(2)/3 and sqrt(3)/2 right sir
|dw:1384484135825:dw|
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