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# C3-trig

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1. hi can someone solve this
3secsquaredX-4=0

can someone help me
2. (Original post by otrivine)
hi can someone solve this
3secsquaredX-4=0

can someone help me
You could write sec in terms of cos
3. (Original post by otrivine)
hi can someone solve this
3secsquaredX-4=0

can someone help me

Remember,
4. 3/cos^2 (x) = 4
cos^2(x) = 3/4
cos (x) = root3/2
x = pi/6 or 30 degrees
5. (Original post by r_t)
3/cos^2 (x) = 4
cos^2(x) = 3/4
cos (x) = root3/2
x = pi/6 or 30 degrees
It will be better to give OP some hints, so that he does it himself, rather than post a full solution for him.

By the way, your solution isn't completely correct.

You haven't considered the negative case.
6. (Original post by raheem94)

Remember,
i get it so secX=3/4 and you invert it and change the root to +4/3 then do cos-1(root3/2)
7. (Original post by otrivine)
i get it so secX=3/4 and you invert it and change the root to +4/3 then do cos-1(root3/2)
secX does not equal 3/4
8. (Original post by otrivine)
i get it so secX=3/4 and you invert it and change the root to +4/3 then do cos-1(root3/2)
I am not understanding what you are trying to do.

Do you get it?
9. (Original post by raheem94)
I am not understanding what you are trying to do.

Do you get it?
ohhh yes yes i get it now
and one more thing for this question tansquared2X-2sec2x+1=0
i got 90 degrees and one maths error is this correct so far or not?
as for the equation i got secsquared2x-2sec2x+1=0
10. (Original post by otrivine)
ohhh yes yes i get it now
and one more thing for this question tansquared2X-2sec2x+1=0
i got 90 degrees and one maths error is this correct so far or not?
as for the equation i got secsquared2x-2sec2x+1=0
It isn't correct.

Remember,

So the equation becomes,
11. (Original post by raheem94)
It isn't correct.

Remember,

So the equation becomes,
yes that is what i got but my answer are wrong

i applied quadratic formula X2-2X+0 which gives 2 and 0
12. (Original post by otrivine)
yes that is what i got but my answer are wrong

i applied quadratic formula X2-2X+0 which gives 2 and 0
Factorise
13. (Original post by otrivine)
yes that is what i got but my answer are wrong

i applied quadratic formula X2-2X+0 which gives 2 and 0
You don't need to apply the quadratic formula,

So you get 2 equations,
14. (Original post by steve2005)
Factorise
yes i get same answer 0 , 2
15. (Original post by raheem94)
You don't need to apply the quadratic formula,

So you get 2 equations,
i get 90 degrees and maths error

and then i takeaway 90 with 360 then keep dividing by 2 correct?

cause my book i giving me only 2 solution 0,180
16. (Original post by otrivine)
yes i get same answer 0 , 2
See my previous post.

0 and 2 are correct because the 2 equation are sec2x=0 and sec2x=2.

But you need to use to find the values of '2x' and hence 'x'
17. (Original post by otrivine)
i get 90 degrees and maths error

and then i takeaway 90 with 360 then keep dividing by 2 correct?

cause my book i giving me only 2 solution 0,180
18. (Original post by raheem94)
See my previous post.

0 and 2 are correct because the 2 equation are sec2x=0 and sec2x=2.

But you need to use to find the values of '2x' and hence 'x'
ok so dont we have to do firstly cos-1(0) then divide by 2 ?
19. (Original post by raheem94)
yes its the edexcel c3 text book
20. (Original post by otrivine)
i get 90 degrees and maths error

and then i takeaway 90 with 360 then keep dividing by 2 correct?

cause my book i giving me only 2 solution 0,180
I think you are looking at the wrong answers.

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