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C3 Practice Paper help

http://files.physicsandmathstutor.com/download/Maths/A-level/C3/Solutionbank-Heinemann/C3%20Practice%20Paper.pdf

In Q2(a), how do we find the area of the triangle? I'm confused with the solution that's given here in the solution bank.
Original post by sabahshahed294
http://files.physicsandmathstutor.com/download/Maths/A-level/C3/Solutionbank-Heinemann/C3%20Practice%20Paper.pdf

In Q2(a), how do we find the area of the triangle? I'm confused with the solution that's given here in the solution bank.


POQ is a right-angle triangle. P is on the y-axis so that's when the curve has x=0. That will be the height of the triangle. Q is found by forming an equation which is tangent to P then seeing where it crosses the x-axis. This will be the length of the triangle.

1/2 * Height * length = your area.

Red is the curve, blue is the tangent line, and green is the area you need:
SDSAD.PNG
(edited 7 years ago)
Original post by sabahshahed294
http://files.physicsandmathstutor.com/download/Maths/A-level/C3/Solutionbank-Heinemann/C3%20Practice%20Paper.pdf

In Q2(a), how do we find the area of the triangle? I'm confused with the solution that's given here in the solution bank.


The area of a triangle is 12bh \frac{1}{2}bh . P is where the curve meets the y axis so the y coordinate of P is the height of the triangle. Where the tangent to the curve meets the x axis (Q) is the other corner, and since the triangle is right angled the x coordinate of Q must be the base. So you need to find the coordinates of P and Q. Start with P, which is where the curve intersects the y axis.
Original post by RDKGames
POQ is a right-angle triangle. P is on the y-axis so that's when the curve has x=0. That will be the height of the triangle. Q is found by forming an equation which is tangent to P then seeing where it crosses the x-axis. This will be the length of the triangle.

1/2 * Height * length = your area.

Red is the curve, blue is the tangent line, and green is the area you need:
SDSAD.PNG


Your diagram helped me out, thanks!

Original post by sindyscape62
The area of a triangle is 12bh \frac{1}{2}bh . P is where the curve meets the y axis so the y coordinate of P is the height of the triangle. Where the tangent to the curve meets the x axis (Q) is the other corner, and since the triangle is right angled the x coordinate of Q must be the base. So you need to find the coordinates of P and Q. Start with P, which is where the curve intersects the y axis.


Yes, I got what to do now. Thanks for your time! :smile:

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