Solved, thank youWatch

#1
Edit: solved
0
7 years ago
#2
Part 1 shows you that the equation you have to solve in the second part, can be written as .

If you let cos(x) = t, and rewrite the equation, the solution should become clearer.
0
7 years ago
#3
1
7 years ago
#4
(Original post by The Muffin Man_)
Hi there, I have this question (shown below) for which 8(a) I've solved and got the required solution, but am not sure how this is used in 8(b) and what to do in 8(b) - could someone help me with this, please?

Think about what Sin^2(x) is equal to.
0
7 years ago
#5
I got: 75.5, 284.5, 435.5 and 644.5 as the answers, is this correct?
0
#6
(Original post by EEngWillow)
Part 1 shows you that the equation you have to solve in the second part, can be written as .

If you let cos(x) = t, and rewrite the equation, the solution should become clearer.
I have cos(x) = 1/4 (disregarding cos(x) = 2) and have got 75.5 from the inverse. Now I'm just not sure of how you take 75.5 from 360/add to 360 and whatnot for the solutions...
0
7 years ago
#7
You now have the same terms in one equation so like a normal quadratic equation just factorise, don't get put off by the fact it's cosx and cos^2x you can do it
0
7 years ago
#8
(Original post by Hemzo)
I got: 75.5, 284.5, 435.5 and 644.5 as the answers, is this correct?
0
7 years ago
#9
(Original post by The Muffin Man_)
I have cos(x) = 1/4 (disregarding cos(x) = 2) and have got 75.5 from the inverse. Now I'm just not sure of how you take 75.5 from 360/add to 360 and whatnot for the solutions...
Draw the graph. Always helps if you aren't sure.
1
7 years ago
#10
Remember that .
So, substitute it in!
0
#11
(Original post by EEngWillow)
Draw the graph. Always helps if you aren't sure.
Ah that helped immensely; I have all of the solutions now. Thank you very much!
1
7 years ago
#12
(Original post by The Muffin Man_)
Ah that helped immensely; I have all of the solutions now. Thank you very much!
No problem. Get in the habit of drawing graphs, they help.
0
7 years ago
#13
Allow Graphs, CAST diagram is the way forward!
0
X

new posts
Latest
My Feed

Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

University open days

• Cardiff Metropolitan University
Sat, 27 Apr '19
• University of East Anglia
Could you inspire the next generation? Find out more about becoming a Primary teacher with UEA… Postgraduate
Sat, 27 Apr '19
• Anglia Ruskin University
Health, Education, Medicine and Social Care; Arts, Humanities and Social Sciences; Business and Law; Science and Engineering Undergraduate
Sat, 27 Apr '19

Poll

Join the discussion

Have you registered to vote?

Yes! (553)
37.82%
No - but I will (115)
7.87%
No - I don't want to (103)
7.05%
No - I can't vote (<18, not in UK, etc) (691)
47.26%