A-Level Edexcel Core Maths C3 January 2011 Q8a : ExamSolutions

[ExamSolutions_Maths]

@TheXeno94 Of course it will but we gennerally don't when there is a constant on the top.

[ExamSolutions_Maths]

There is more to it than that. Use the quotient rule when you have a function of x on the top and bottom of a fraction. Check out my tutorials on this on my website for a clearer and more detailed explanation.

[ExamSolutions_Maths]

Why? what way would you have it done then? The quotient rule is possible but a bit over the top.

[fragitza]

I started off doing it using quotient then saw you used chain rule. So for simplicity, if you ever see a reciprocal try and rearrange to use chain right?

[frogambassador]

The question just says to prove that if y = 1/cos x, then dy/dx = sec x tan x. Do you actually lose marks if you use the quotient rule instead?

[fragitza]

Why are you changing it to chain rule?

[BexJLSLover]

If you use the quotient rule, do you still get all the marks?
But it's easier to use the chain rule when there's a constant on top?

[ExamSolutions_Maths]

Not at all. Seems an unnecessary method though.