Trigonometry

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Verify the identities please.
1.) TAN(X+π)-TAN(π-X)= 2 TAN X

2.) SIN(X+Y)+SIN(X-Y)= 2 SIN X COS Y

  • Trigonometry -

    1. by the CAST rule
    tan(π+Ø) = tanØ
    tan(π-Ø) = -tanØ

    LS = tan(x+π) - tan(π-x)
    = tanx - (-tanx)
    = 2tanx
    = RS

    2. again one of the standard identities used on the LS

    LS = sinxcosy + cosxsiny + sinxcosy - cosxsiny
    = 2sinxcosy
    = RS
    btw, 2sinxcosy = sin (2x) which would be a simplification of the RS

  • Trigonometry -

    AWESOME! SUPERB! I had it right when you provided support. THANKS!

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