Year 12s: what will be the first way you research your future options? >>

C1 doubts

Scroll to see replies

@Hamoody96

With all due respect. You shouldn't be giving out help, if you're not 100% sure of what you're talking about. The questions ask for the roots, which also means solutions. So you do complete the square to find these roots, but using the discriminant only determines the type of roots an equation has.

to be accurate one should only refer to the solution of an equation; the solution comprises the root or roots.

:hat2:

Reply 21

MiladA

For Q5 part (a) it says complete the square leaving the expression in terms of k. Use this for part (b) to solve the equation. To find k compare the two equations and see how to make the second equal to the first (the coefficients). Once you have found the value of k that satisfies this, substitute it into the expression from part (a) and solve for x from there.

(edited 7 years ago)

Reply 22

MiladA

For Q6 part (b), it is useful to have knowledge on how to manipulate series, you can split the terms into separate series (however this isn't C1 material, it's FP1 but it's very easy to learn this method). As the sum is going from r=1 to n, you can use the standard result of the sum of r terms (r going from 1 to n) in the formula book if you use the method.

However, at this stage what you probably want to do is list the first few terms, then the nth term (when r=n). Come up with a general formula and then manipulate into the required form.