TRIG on DAT!?

[Jman1984]

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I'm noticing that Destroyer has a ton of trig questions such as:

Evaluate: 5/secx-tanx given that sec^2x = 1+tan^2 x

I will never understand these....even if my life depended on it.

If anyone knows of an easy way of understanding these, please explain.

For those who have already taken the DAT...do trig functions like this show up or will I be safe just knowing SOHCAHTOA and common triangles ==> 45-45-90 = 1:1:squareroot2 30-60-90 = 1:squareroot3:2

Thanks in advance!

 

[Streetwolf]

I'm noticing that Destroyer has a ton of trig questions such as:

Evaluate: 5/secx-tanx given that sec^2x = 1+tan^2 x

I will never understand these....even if my life depended on it.

If anyone knows of an easy way of understanding these, please explain.

For those who have already taken the DAT...do trig functions like this show up or will I be safe just knowing SOHCAHTOA and common triangles ==> 45-45-90 = 1:1:squareroot2 30-60-90 = 1:squareroot3:2

Thanks in advance!

Dunno what they want for the trig thing...

You could do sec^2x - tan^2x = 1... then notice that you have a difference of squares. So it equals (secx + tanx)(secx - tanx) and then notice that the subtraction one is in the denominator. If you multiply the fraction by (secx+tanx)/(secx+tanx) then you'll get:

5(secx+tanx) / (sec^2x + tan^2x) = 5(secx+tanx)/1 = 5(secx + tanx)

Is that what they want?

 

[Jman1984]

Yeah that's the answer they are looking for! You actually helped me understand it too! Thanks!

 

[jay47]

This really doesn't even seem useful to me at all... I mean, not that a mathematics major might not use it...but where in the real world would this sort of maddening trig come in useful?

 

[bennijai]

Don't worry DAT trig is very basic*

*As long as you know your trig identities of course.

 

[EyEnStein 07]

This really doesn't even seem useful to me at all... I mean, not that a mathematics major might not use it...but where in the real world would this sort of maddening trig come in useful?

umm a lot probably...astronomy, geography, physics, engineering construction, buildings, anything that involves measurments pretty much...not that it would require sec tan etc... but i mean..it could come in handy i suppose.