i have about 4 problems here all together

my first problem is this question letter H , below is my working out but my answer seems to be wrong so i dont know what im doing wrong.

Find the equation of (i) the tangent and (ii) the normal to the curve.

my working

answer in the back is

i) 17x - y + 27 = 0

ii) x + 17y + 121 = 0

the other 3 problems are

answers

3: x = 1/2

4: 87'53'

5: x = 1/3/4

in my text book it doesnt really give me examples directly related to this question to solve it so im quite clueless on question 3 , 4 and 5. The other questions in this chapter are primarily based on questions like 4 and 5. So if someone can help me with those questions i'll be able to do the rest.

thx all help is appreciated.