Найти производную: y=tg x - ctg x y=⁴√x^6+√x^8 y=2x²-5x+7

1) y = tg x - ctg x
y' = 1/Cos²x + 1/Sin²x = (Sin²x + Cos²x)/Sin²xCos²x = 1/Sin²xCos²x =
= 4/4Sin²xCos²x = 4/Sin²2x
2) y=⁴√x^6+√x^8= x^6/4 + x^4 = x^3/2 + x^4
y' = 3/2*x^1/2 + 4x^3= 3√x/2 + 4x^3
3) y=2x²-5x+7
y' = 4x -5