IGCSE Add Maths May 2016 Paper 11 Doubt regarding degree and radians

In the graphical question, where we had to find the area under the cos graph by integrating it, i used degree instead of radians. That question was for 8 marks and so i am really scared. But all my steps were correct. Will they cut all the marks ?

They will award some of the marks, there will be method marks for the integration steps you correctly performed. Try and find a similar question on a past paper and use the mark scheme for that paper to give you an idea of how many marks you might be awarded. I suspect you'll get 2 or 3 marks but without seeing the exact question and your answer it's hard to tell.

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Thank u so much for your reply.

This is just to give u an idea of the question: We were given a cos graph, and we had to find its maximum point ( labelled B ) and the point where it intersects the x axis ( labelled A ). Finding A and B were two separate parts of the questions holding 2 marks each.
The third part was to find the area between the points A and B for 4 marks.
Since, I did parts 1 and 2 in degrees, the ans for the third part is wrong. Thought, all my steps are clearly mentioned.

How many marks do u think i will lose now and how do u determine where to use radians and where to use degrees?

Thanks in advance

If you are told the graph is drawn between 0 and pi or -pi to pi or similar limits that mention fractions or multiples of pi you know the question requires radians.
WHENEVER the question involves differentiation or integration of trigonometric functions the question has to be done in radians.

I'm not familiar enough with their marking guideline to be certain but my guess is that you will be awarded 3-4 of the available marks.


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