Question is:

Use Pythagorean identities to write the expression as an integer.

Attached is the expression.

How would you solve this one?

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- Dec 17th 2008, 10:05 AMmwokPythagorean Identities to write expression as integer
Question is:

Use Pythagorean identities to write the expression as an integer.

Attached is the expression.

How would you solve this one? - Dec 17th 2008, 10:16 AMrunning-gag
Hi

sec x is the hypotenuse of a right-angle triangle whose other sides are tan x and 1

Therefore $\displaystyle 1 + tan^2x = sec^2x$

Then $\displaystyle tan^2x - sec^2x = -1$

List of trigonometric identities - Wikipedia, the free encyclopedia - Dec 17th 2008, 10:19 AMmwok
- Dec 17th 2008, 10:24 AMChris L T521
- Dec 17th 2008, 10:25 AMrunning-gag
You are asked to write the expression as an integer

Whatever x

$\displaystyle tan^2x - sec^2x = -1$

If you like whatever $\displaystyle \beta$

$\displaystyle tan^2(4\beta) - sec^2(4\beta) = -1$

EDIT : beaten by Chris ! - Dec 17th 2008, 10:27 AMmwok
- Dec 17th 2008, 10:31 AMrunning-gag
- Dec 17th 2008, 10:39 AMmwok
Okay, is this correct (different equation but same question).

- Dec 17th 2008, 10:52 AMrunning-gag
Not exactly

$\displaystyle csc^2\theta-cot^2\theta=1$ - Mar 7th 2010, 03:19 PMrasczak
- Mar 7th 2010, 03:56 PMpurplec16
Because $\displaystyle tan^2 - sec^2 is = -1$ it is the same as saying $\displaystyle 1+ tan^2 4\beta= sec^2 4 \beta$

$\displaystyle tan^2 4 \beta - sec^2 4 \beta = -1$

pretty much the $\displaystyle 4 \beta$ doesnt matter it is jus like $\displaystyle \theta$