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/Cos ²x + 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