Trigonometry revisited

show that the equation secθ + cosecθ = c has two solutions between 0 and 2π if c2 < 8 and four solutions if c2 > 8.

I've tried but didn't get the correct answer.

14 Answers

1
Sunil Kumar ·

hey someone try..........

19
Debotosh.. ·

yes, trying..please wait a bit!

1
Sunil Kumar ·

I've got the answer. If someone need the solution. do tell me I'll post it..........

11
Devil ·

Use the fact that secx+cosecx=\frac{2\sqrt{1+sin2x}}{sin2x}
Now use quadratic -type-arguments.

19
Debotosh.. ·

aree...i am posting the whole solution,,,just wait!

1
Sunil Kumar ·

meanwhile I've got one more question.

xsecθ - ztanθ = w
ysecθ + wtanθ = z

I tried this question 2-3 times but was't gettin the answer.
i've tried squaring both the equations and adding those.

but my answer doesn't match the options....

11
Devil ·

So what do we have to do?

1
Sunil Kumar ·

@soumik, so try solving it. The answer is x2 + y2 = z2 + w2.
If u get this answer then post the solution..

19
Debotosh.. ·

well, what my solution says is that we should better proceed by graphs , after an elementary summary of the various values of the given equation ..the table comes up as below!

based on this given data we can construct the graph as follows

thus, its work done mr.sunil !

1
Sunil Kumar ·

great work.........
However I've not done this way.... My answer is :-

19
Debotosh.. ·

that is nice !

1
Sunil Kumar ·

But I think your method is more good. Thanks for the answer........

1
Sunil Kumar ·

@organic . what about the 2nd question........
if
xsecθ - ztanθ = w
ysecθ + wtanθ = z then show that

x2 + y2 = z2 + w2.

11
Devil ·

x=wcos\theta+zsin\theta
And
y=zcos\theta-wsin\theta
Square both x and y, and add them up.

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