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Maths

I don’t quite understand the solution in the ms, what I have done is find the gradient of the perpendicular line which is sin(theta)/cos(theta) and then negative reciprocal to find the line RP which gives -cot4A642550-4260-430E-85DE-283DAA65E5F9.png39F3D2E4-71D3-4A5D-B34F-A5EF4C807B97.jpeg4D8993DE-7F5C-4699-8D27-9B66CDB90525.png
(edited 2 years ago)
Original post by The A.G
I don’t quite understand the solution in the ms, what I have done is find the gradient of the perpendicular line which is sin(theta)/cos(theta) and then negative reciprocal to find the line RP which gives -cot

Check your diagram - have you marked theta correctly? A quick look suggests it is 90 - theta
Original post by Muttley79
Check your diagram - have you marked theta correctly? A quick look suggests it is 90 - theta

My bad, you’re right.

How would deduce that it’s 90-theta quickly.I used quadrilateral, or similar triangles but both takes long in my opinion
(edited 2 years ago)
Original post by The A.G
My bad, you’re right.

How would deduce that it’s 90-theta quickly.I used quadrilateral, or similar triangles but both takes long in my opinion

If you draw the line from Q to the x-axis it's clearer

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