Soal Bentuk 2tan X 1 Tan 2 X Ekuivalen Dengan Bentuk
If sinx=7/5 and angle x is in quadrant 2 and cos y=12/13 and angle y is in quadrant 1 find sin (xy) asked in TRIGONOMETRY by harvy0496 Apprentice doubleangleExplanation To prove sin2x = 2tanx 1 tan2x Let us start from R H S and prove it equal to L H S RH S = 2tanx 1 tan2x ⇒ 2tanx sec2x, as 1 tan2x = sec2x,identity ⇒ 2( sinx cosx) 1 cos2xcosx ⇒ 2sinxcosx = sin2x as per sin2x = 2sinxcosx identity
