Maths AS past paper questions (C1 and C2)

Could someone please help me with the following questions..


So I did (a) but couldn't solve (b) and (c)?

This one too ..

You'll need to be more specific about this one.

I don't know how to solve (a),(b)and (c) ??

Could someone please help me with the following questions..


So I did (a) but couldn't solve (b) and (c)?


I couldn't solve this question..

This one too ..

I got 40 and 5/8 for the logarithm question.

Yeah, I actually just solved it now!!
Thank you!!

(a) is the cosine curve shifted pi/3 to the right; there's not much I can do to explain it, you should know your trig graphs and your function transformations.

(b) is just $\cos y = 0$ (which you should know how to solve) and then back-substitute $y = x - \frac{\pi}{3}$ and solve for $x$.

(c) is just $\cos y = \frac{1}{\sqrt{2}}$ (Which you should know how to solve, one of the solutions is $y = \frac{\pi}{4}$) and then back-sub and solve for $x$.

Perhaps you need to work on your concepts more before moving on to past papers?

Could someone please help me with the following questions..


So I did (a) but couldn't solve (b) and (c)?


I couldn't solve this question..

This one too ..

For the Geometric sequences:
a)You use ar^n-1 a=300 r=1.05 n=24 so: 300*(1.05)^23=921.46=922 phones
b)You use the summation formula. I substituted the values in and I got 13351
c) You have to use ar^n-1 again:
300*1.05^N-1>3000
1.05^N-1>10
Take logs:
(N-1)log1.05>log10
N-1>log10/log1.05
N-1>47.19....
N>48.19...
N>48