1) How do I find the value of sin A if tan A = 1/2 using trignometric identities? [/code]
C cllynn213 New member Joined Dec 24, 2005 Messages 13 Dec 28, 2005 #1 1) How do I find the value of sin A if tan A = 1/2 using trignometric identities? [/code]
U Unco Senior Member Joined Jul 21, 2005 Messages 1,134 Dec 28, 2005 #2 G'day, You could use the identities: cos2θ+sin2θ=1 \displaystyle \, \cos^2{\theta} + \sin^2{\theta} = 1\,cos2θ+sin2θ=1 and tan2θ+1=sec2θ \displaystyle \, \tan^2{\theta} + 1 = \sec^2{\theta}\,tan2θ+1=sec2θ. Alternatively you could draw a right-angled triangle with tanA=12\displaystyle \tan{A} = \frac{1}{2}tanA=21 and find sinA \displaystyle \, \sin{A}\,sinA from there.
G'day, You could use the identities: cos2θ+sin2θ=1 \displaystyle \, \cos^2{\theta} + \sin^2{\theta} = 1\,cos2θ+sin2θ=1 and tan2θ+1=sec2θ \displaystyle \, \tan^2{\theta} + 1 = \sec^2{\theta}\,tan2θ+1=sec2θ. Alternatively you could draw a right-angled triangle with tanA=12\displaystyle \tan{A} = \frac{1}{2}tanA=21 and find sinA \displaystyle \, \sin{A}\,sinA from there.
