Edexcel M1 June 2013 Question 3, do I get full marks?

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It's actually quite similar. That would get you full marks. Well done on the presentation and layout, it's very neat and readable; any examiner would be impressed!

Thank very much! I was just worried about the way I did the angel, I found alpha as a decimal and just used it that way.

Thanks

Thank very much! I was just worried about the way I did the angel, I found alpha as a decimal and just used it that way.

Thanks

The reason they give you $\tan \alpha = \frac{3}{4}$ is so you can find $\cos \alpha$ and $\sin \alpha$ without having to use your calculator.

Since $\tan \alpha = \frac{3}{4}$, you have a right-angled triangle with an acute angle $\alpha$, opposite length 3 and adjacent length 4. So the hypotenuse must be 5 and then working out $\cos\alpha$ and $\sin\alpha$ as fractions is simple.

But you wouldn't lose a mark if you made sure you didn't round the calculator value.

Yes, I think I should get used to doing it that way, its also takes less time!