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2. ### Integration by Substitution

Something of the form (ax+b). Decided to assume that (u) is in that form and so worked it through. Is ln(2) the final answer?
3. ### Integration by Substitution

I have but I thought it had to be a linear expression to use the natural log. It did cross my mind though - this is what to do, then?
4. ### Integration by Substitution

Homework Statement Homework Equations None. Well, dx=du/cosx The Attempt at a Solution I've substituted it in, got new values for the limits but I have u^-1 on the bottom and so can't integrate it from my current knowledge. Basically I'm stuck with: Integration of u^(-1) du...
5. ### Vector Multiplication

Thanks for the reply. I think I realized why I was lost - it's because I was! We haven't been taught this part of vectors yet, and I was looking at a past paper. Haha, oops. The picture was already printed for me and I thought that a=(-c). I better stick to diagrams of squares. :)
6. ### Vector Multiplication

Homework Statement "PRQSTU is a regular hexagon of side 2 units. PQ,QR and RS represent vectors a, b andc respectively. Find the value of a.(b + c) The hexagon is a regular hexagon starting at the far left (ie pointing left) with P then anti clockwise through U at the top left...
7. ### Trigonomic Equation

Thank you! I just figured out what you were saying. I didn't see it as a quadratic equation at all - oh dear (exam in 4 day, haha). Figured it out, now just need to calculate the actual angles invovled. Thanks again. Mark
8. ### Trigonomic Equation

Hi. Thanks for the reply. I've never been taught how to do that, so is there another way of doing it? Thanks again, Mark
9. ### Trigonomic Equation

Homework Statement Solve the following trigonomic equation for 0<=x360<= : 5cos2x + cosx + 2 = 0 Homework Equations Not sure what goes here but I've been trying to substitute these - cos2x = cos^2x - sin^2x cos2x = 2cosx^2 - 1 - I think this is the correct one to use. cos2x = 1 -...