y = arcsin x
therefore
x = sin y
dy/dx = 1 / [ dx/dy ] Substituting : d(arcsin x)/dx = 1 / [ d(sin y)/dy ] = 1/cos y But cos 2 y = 1 sin 2 y and sin y = x Substituting : cos 2 y = 1 x 2 ![]() |
sin π/6 = 1/2
arcsin ( π/6 ) = 1/2 + [ 1 × (1/2) 3 ] / [ 2 × 3 ] + [ 1 × 3 × (1/2) 5 ] / [ 2 × 4 × 5 ] + [ 1 × 3 × 5 × (1/2) 7 ] / [ 2 × 4 × 6 × 7 ] + ... = 1/2 + 1/48 + 3/1280 + 15/43008 + 105/1769472 ... = .52359 ... π = 6 × .52359 ... = 3.1415 ... continue adding terms for accuracy |