prove: SinA TanA= 1-cos^2A/cosA
S soroban Elite Member Joined Jan 28, 2005 Messages 5,586 Nov 8, 2005 #2 Hello, yasaminG! Prove: .\(\displaystyle \sin(A)\cdot\tan(A)\:=\:\frac{1\,-\,\cos^2(A)}{\cos(A)\) Click to expand... The left side is: .sin(A)⋅sin(A)cos(A) = sin2(A)cos(A) = 1 − cos2(A)cos(A)\displaystyle \sin(A)\cdot\frac{\sin(A)}{\cos(A)}\;=\;\frac{\sin^2(A)}{\cos(A)}\;=\;\frac{1\,-\,\cos^2(A)}{\cos(A)}sin(A)⋅cos(A)sin(A)=cos(A)sin2(A)=cos(A)1−cos2(A)
Hello, yasaminG! Prove: .\(\displaystyle \sin(A)\cdot\tan(A)\:=\:\frac{1\,-\,\cos^2(A)}{\cos(A)\) Click to expand... The left side is: .sin(A)⋅sin(A)cos(A) = sin2(A)cos(A) = 1 − cos2(A)cos(A)\displaystyle \sin(A)\cdot\frac{\sin(A)}{\cos(A)}\;=\;\frac{\sin^2(A)}{\cos(A)}\;=\;\frac{1\,-\,\cos^2(A)}{\cos(A)}sin(A)⋅cos(A)sin(A)=cos(A)sin2(A)=cos(A)1−cos2(A)
