SOLUTION: If tanα =4/3 and cosβ = 12/13, where 0<β<α<90°, evaluate without using tables.
a) sin 2α
b) tan 2α
c) cos(α-β)
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-> SOLUTION: If tanα =4/3 and cosβ = 12/13, where 0<β<α<90°, evaluate without using tables.
a) sin 2α
b) tan 2α
c) cos(α-β)
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Question 541148: If tanα =4/3 and cosβ = 12/13, where 0<β<α<90°, evaluate without using tables.
a) sin 2α
b) tan 2α
c) cos(α-β) Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! f tanα =4/3 and cosβ = 12/13, where 0<β<α<90°, evaluate without using tables.
a) sin 2α
b) tan 2α
c) cos(α-β)
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tan α=4/3
sin α=4/5
cos α=3/5
cos β=12/13
sin β=5/13
..
a) sin 2α=2sin α cos α=2*4/5*3/5=24/25
b) tan 2α=(2tan α)/(1-tan^2α)=(8/3)/(1-16/9)=(8/3)/(-7/9)=-72/21
c) cos(α-β)=cos α cos β-sin α sin β=3/5*12/13-4/5*5/13=36/65-20/65=16/65
please check my calculations
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