C3-trig

OP

Original post by steve2005

I think you are looking at the wrong answers.

i think they made a mistake im not sure i am checking again it says 0,180 thats why i am a bit confused if my answers are wrong or right?

Reply 21

raheem94

13

Original post by otrivine

yes its the edexcel c3 text book

Page No?

You are probably looking at the wrong answers, i get different answers.

Reply 22

raheem94

13

Original post by otrivine

i think they made a mistake im not sure i am checking again it says 0,180 thats why i am a bit confused if my answers are wrong or right?

What are your answers?

Reply 23

Yorrap

2

You wrote the question wrong.

It's tan²θ = sec2θ -1 for 0 < θ < 180 (not = 2sec2θ -1)

so you get

sec2θ = 0 and sec2θ = 1
not possible and cos2θ = 1
then you solve 2θ for 0 < 2θ < 360 and get;
2θ = 0^o, 360^o
θ = 0^o, 180^o

(edited 11 years ago)

Reply 24

otrivine

OP

14

Original post by raheem94

Page No?

You are probably looking at the wrong answers, i get different answers.

page 97 question 8)g) ex 6D

Reply 25

raheem94

13

Original post by otrivine

page 97 question 8)g) ex 6D

You wrote the question as: secsquared2x-2sec2x+1=0 which is

sec^22x-2sec2x+1=0

The actual question is:

tan^22x=sec2x-1

Reply 26

otrivine

OP

14

Original post by raheem94

You wrote the question as: secsquared2x-2sec2x+1=0 which is

sec^22x-2sec2x+1=0

The actual question is:

tan^22x=sec2x-1

no i gave you in that form cause i applied the formula and when you applied the formula you get that eqaution

Reply 27

otrivine

OP

14

Original post by Yorrap

You wrote the question wrong.

It's tan²θ = sec2θ -1 for 0 < θ < 180 (not = 2sec2θ -1)

so you get

sec2θ = 0 and sec2θ = 1
not possible and cos2θ = 1
then you solve 2θ for 0 < 2θ < 360 and get;
2θ = 0^o, 360^o
θ = 0^o, 180^o

wait please cos-1(0) gives u 90?