Here’s the video to solve 2 questions regarding composite and inverse function. It is a Paper 1 question, carries 4 marks,

Enjoy

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question 2,

where did the “9” come from?

the “-9″/3??

Hi race, I believe i explained where did the 9 come from. It’s part of the solution for the fraction, making the denominator to be a 3 so that it’s the same as the (2x-8)/3. Hence, you can simplify (2x-8-9) / 3 = (2x-17) / 3

thanks !

can i ask something? why must the final answer (a)must over 3? and why not the answer only 2x-17?

Hi nash, because g(x) inverse is (x-4)/3. When you sub this into the composite function, the over 3 is still there. If it’s only 2x-17, then what happens to your (x-4)/3 from the beginning? Watch the video again and listen to my explanation carefully.

😀 okayss~ anyway thanx Ms Ng.

its k…i managed to find ques 2……

exf(x)=4x=k

g(x)=x-2

fg(x)=mx+8

how to find the value of m and k ??

f(x)=4x=k

g(x)=x-2

fg(x)=mx+8

how to find the value of m and k ??

miss ng…how u got the inverse function for h is x-4 over 3??

esteryeojh95, u have to do fg(x)first and then compare it wit the eqn fg(x)=mx+8

thx 4 the tutorial…it really helped me..!

thnks miss ng