Exo 1
https://www.wolframalpha.com/input/?i=z%5E2-sqrt(3)z%2B1%3D0

Exo 2
https://www.wolframalpha.com/input/?i=sqrt(3)%2Bi

https://www.wolframalpha.com/input/?i=1%2Bi

https://www.wolframalpha.com/input/?i=(sqrt(3)%2Bi)%5E3%2F(1%2Bi)%5E2

Exo 3
https://www.wolframalpha.com/input/?i=(a%2Bb)%5E5

https://www.wolframalpha.com/input/?i=cos(5theta)

Exo 4
https://www.wolframalpha.com/input/?i=limit+of+(x%5E3-3x%5E2-x%2B3)%2F((x-1)(x-2))+when+goes+to+1

https://www.wolframalpha.com/input/?i=limit+of+(xexp(-10x)%2B2exp(2x)%2Bx%5E5)%2F(x%5E2017%2Bcos%5E2(x)%2B8exp(2x))+when+x+goes+to+infinity

Exo 5
https://www.wolframalpha.com/input/?i=derivative+of+cos(sqrt(1%2Bx%5E2))

https://www.wolframalpha.com/input/?i=derivative+of+(ln(x)%2Bx^2)%2F(sqrt(1%2Bx^2))

Exo 6
https://www.wolframalpha.com/input/?i=limit+of+1%2Fx*(sqrt(1%2Bx%5E2)-sqrt(1-x%5E2))+as+x+goes+to+0

https://www.wolframalpha.com/input/?i=derivative+of+1%2Fx*(sqrt(1%2Bx%5E2)-sqrt(1-x%5E2))

https://www.wolframalpha.com/input/?i=1%2Fx*(sqrt(1%2Bx%5E2)-sqrt(1-x%5E2))