A level ocr parametric differentiation question…again

for part b i’m close to the form they want it in but i have theta cos sec^3 theta but i only need theta sec^2 theta
but the mark scheme is so weird and confusing

it makes more sense when u see the question

https://imgur.com/a/oLnHmnz

Reply 1

mqb2766

You were close 1/2 way down.
3 theta cos(theta) sec^3(theta)
becomes ... (look at the answe)

and
3 sin(theta) sec^3(theta)
becomes (again look at the answer)

Reply 2

MalarckyS2

Original post by esha06

for part b i’m close to the form they want it in but i have theta cos sec^3 theta but i only need theta sec^2 theta
but the mark scheme is so weird and confusing
it makes more sense when u see the question
https://imgur.com/a/oLnHmnz

Cos theta = (sec theta)^-1 or 1/(sec theta) so -1 + 3 = 2 (indicies laws)

Reply 3

esha06

Original post by mqb2766

You were close 1/2 way down.
3 theta cos(theta) sec^3(theta)
becomes ... (look at the answe)
and
3 sin(theta) sec^3(theta)
becomes (again look at the answer)

ohhhhhh yeahhhh i realised the sin bit becomes tan sec^2 i just hadn’t realised u literally do the sam thing for the cos part 🤦🏽*♀️🤦🏽*♀️