If sina+7sinb=4 (sinc+2sind) and cosa+7cosb=4

If sina+7sinb=4 (sinc+2sind) and cosa+7cosb=4 (cosc+2cosd), how do I prove that 2cos(a-d) =7cos(b-c)?
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2. asked by Anonymous
3. 444 views
If sina+7sinb=4 (sinc+2sind) and cosa+7cosb=4 (cosc+2cosd), how do I prove that 2cos(a-d) =7cos(b-c)?
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2. asked by Alexa
3. 877 views
Hi, can someone give me the answer to this question:secA-tanA=1/4. Find cosA I got: CosA=4(1-sinA) Is my answer good? Now
1. 2 answers
2. asked by Shym
3. 926 views
Hello I am having trouble with proving this:sinA/secA+secA/cscA = tan(A)(2-sin^2(A)) So far I've gotten SinA/(1/cosA) +
1. 1 answer
2. asked by Jimbo
3. 800 views
Prove that [sinA/(1-cosA)-(1-cosA)/sinA]*[cosA/(1+sinA)+(1+sinA)/cosA]=4cosecAI the second part as 2 secA
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2. asked by Agastya
3. 733 views
Let P=(cosA sinA)(sinA cosA) Q=(cosB sinA) (sinB cosA) show that PQ=(cosA(A-B) sin(A B)) (sinA(A B) cos(A-B))
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2. asked by James
3. 716 views
Given that sinA=2/5 and that A is obtuse,find the value of cosA.👍 0 👎 0 👁 25 asked by Raj yesterday at 4:18am sinA =
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2. asked by Raj
3. 1,208 views
if cos(B-C)+cos(C-A)+cos(A-B)=-3/2 then prove that cosA+cosB+cosC=O and sinA+sinB+sinC=O after that prove that
1. 1 answer
2. asked by Binoy kumar mahato
3. 2,316 views
CosA/1+sinA=1-sinA/cosAI have to prove the identity each side has to b the same how would i do that? I have a unit test on
1. 5 answers
2. asked by Kristien
3. 621 views
I need to count this:a) 1-tg^2a/1+ctg^2a, when sina =2/3 b) 1-tg^2a/1-ctg^2a, when cosa= -1/3 c) tga * cos^2a, when sina +
1. 1 answer
2. asked by Evelina
3. 613 views