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Recall formulas consistently throughout the day and u will memorise them eg. When u are doing nothing, think of trig identities, "double angles now, sin2A = 2sinAcosA, ok, cos2A = cos^2 A - sin^2 A = two other ones" If u can recall ALL trig identities, now start doing textbook questions to...

Maths - understand the basics by textbook questions or w/e then hit the past papers

Q2. Axis of symmetry is found by: x = -b/2a Quadratic: y = ax^2 + bx + c So, y=x^2 + 6x - 9 a = 1, b = 6, c = -9 x = -b/2a x = -6/2(1) x = -3 Q3. Method 1: Sub x = -3 into the parabola Method 2: y = x^2 + 6x - 9 Complete the square, y = (x+3)^2 - 18...

Re: HSC 2013 4U Marathon $Let a, b, c be positive real numbers with sum 3. \\ \\ Prove that \sqrt{a} + \sqrt{b}+\sqrt{c} \geq ab + bc + ca

I am not sure about part (a) (maybe minimum displacement is x = 0)

Q12) a) T = 2pi/n (and n= pi/8), so the period of this particle is 16seconds b) Max and min displacement, means max and min values of 'x'. By looking at the graph, we can see that the max and min values for displacement is x = 3 and x = -3 respectively (or if u wanna do it algebraically, find...

made a mistke

Re: HSC 2013 3U Marathon Thread ah ok, thanks

re: HSC Chemistry Marathon Archive Question: Big bob loves sodium hydrogen carbonate because he used this as his primary standard (in which he used to make a standard solution) to calculate the concentration of hydrochloric and sulfuric acid. Explain why you should not conduct titration with...

Re: HSC 2013 3U Marathon Thread can u prove it w/o induction?

Re: HSC 2013 3U Marathon Thread \rightarrow \\ \\ 1.$ Derive 6 equations of motion \\ \\ Trajectory: y = $\frac{-gx^2}{2U^2 cos^2\alpha} + xtan\alpha \\ $Since it passess through (a,b),\\ \\ \therefore b = $\frac{-ga^2}{2U^2 cos^2\alpha} + atan\alpha \\ \\ \therefore...

Triangle (PQR) = Triangle (QPR)

\rightarrow \\ A_{PQR} = \frac{1}{2} \cdot PQ \cdot QR \\ = \frac{1}{2} \cdot 12 \cdot 16 \\\\ = 96 \rightarrow \\A_{QPR} = \frac{1}{2} \cdot QS \cdot PR \\ \\ ~~~~~~=\frac{1}{2}\cdot PR \cdot QS But A_{PQR} = A_{QPR}

Get triangle PQS and QSR, combine them. The resultant area will be the same as triangle PQR

They are the same triangle, look carefully, the 2 right-angled triangles are the SAME Well u can obviously see one triangle is PQR (with right angle on Q) The other triangle is QPR with right angle at S

Thanks, i'll check it out when i have some spare time

Btw please do not look at the answer, it will stuff up ur thinking patterns If u cannot answer a question, try harder and make an AIM to work towards

Look at the TWO BIG right-angled triangles Areas areas are the same, A_1 = A_2 \frac{1}{2}b_1h_1 = \frac{1}{2}b_2h_2 b_1h_1 = b_2h_2 12 x 16 = QR x PR QR = 192/PR Find PR using the glorious Pythagoras theorem

After HSC, I will go hardcore (or maybe i'll play once a week because it releases ALL my stress and relaxes me so much)

U still have time to improve!