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Math Proof Questions

Can someone write the titles of all of the proof questions that come in Pure 1 and 2? I am specifically talking about ones that prove a formula not like "prove that all even numbers are divisible by 2" for example. I mean proofs like the geometric and arithmetic series formulae.

Reply 1

Sorry you've not had any responses about this. :frown: Are you sure you've posted in the right place? :smile: Here's a link to our subject forum which should help get you more responses if you post there. :redface:

Reply 2

Original post by joaofelix
Can someone write the titles of all of the proof questions that come in Pure 1 and 2? I am specifically talking about ones that prove a formula not like "prove that all even numbers are divisible by 2" for example. I mean proofs like the geometric and arithmetic series formulae.

The Fundamental Theorem of Calculus. Look on Khan Academy. Bicen Maths.

Reply 3

Original post by thegeek888
The Fundamental Theorem of Calculus. Look on Khan Academy. Bicen Maths.

Thank you! But what are the other ones in the syllabus if you know?

Reply 4

Original post by joaofelix
Can someone write the titles of all of the proof questions that come in Pure 1 and 2? I am specifically talking about ones that prove a formula not like "prove that all even numbers are divisible by 2" for example. I mean proofs like the geometric and arithmetic series formulae.

I’ve just had a look at the spec to remind myself which topics come up on P1 and P2 (I assume this is the Edexcel IAL course) and these are what I reckon should be covered, though the P1 proofs are suggestions for your own understanding rather than as required by the spec:

P1:

-Proving the quadratic formula (by completing the square).

-Knowing where the formula y - y1 = m(x - x1) comes from (this is simply rearranging the equation for the gradient, y = change in y/change in x).

-Proving the sine and cosine rules may be helpful.

-Proving the equations s = and A = 1/2 θr^2 for a circle, where θ is in radians (this can be done by using the equations c = πd = 2πr and A = πr^2, then multiplying by 180θ/π° (which is the angle within the sector, converted from radians to degrees) and then dividing by 360° (the total angle at the centre of a full circle)).

-By extension, you could show that if a chord is drawn in a sector in such a way that it forms an isoceles triangle with an angle θ and two sides with a length equivalent to that of the radius, the area of the segment created is 1/2 r^2 - sinθ) (this is simply area of sector - area of triangle, where the a = r, so A = 1/2 θr^2 - 1/2 r^2 sinθ => A = 1/2 r^2(θ - sinθ)).

P2:

-There is a whole topic on general methods of proof (deduction, exhausion and disproof by counterexample), but this isn’t what you were asking for.

-Proving Sn = 1/2 n[2a + (n - 1)d] and equivalent forms for an arithmetic sequence.

-Proving Sn = a(1 - r^n)/(1 - r) for a geometric sequence and knowing why the sum to infinity of a geometric sequence with |r| < 1 is a/(1 - r) (if |r| < 1, then r^n decreases as n increases. As such, when n is large, r^n can be neglected and so Sn simplifies to a/(1 - r)).

-Proving the laws of logs may be useful for your own understanding.

-Knowing how to use the identities sin(θ)/cos(θ) = tan(θ) and sin^2(θ) + cos^2(θ) = 1 to prove all sorts of trig statements comes up, but I think proving these identities may be useful for your own understanding (you can try using right-triangles, the definitions of these functions as per SohCahToa etc).
(edited 1 year ago)

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