Thread: Trig Help

I am having trouble finding the period, and amp from ↓ and simplifying

1. Whats the period of the graph of y = 2cos^2 5X -1

period = 2pie/b. I cannot define what the b is. In theory it should be 5, but the power has taken its effect.


2. For y= 5sinXcosX +1, find its amplitude,period, and its range, and its X intercepts X = all real numbers

no idea how to start.^^;

3. simplify sin^2 X + sec^2 X + tan^2 X + cos^2 X
a.2
b. 1+sin^2X/cos^2X
c.2sec^2X
d.2tan^2X

here is what i have done, first finding the common denominator.

= sin^2 X + 1 + Sin^2X + cos^2X
/ cos^2X cos^2X

= (sin^2X)(Cos^2X)+1+Sin^2X+(cos^2X)(cos^2X)
/ cos^2X

then i got stuck..

1 problem per thread please.



Use that to get the expression in a better form.

Originally Posted by hovermet

I am having trouble finding the period, and amp from ↓ and simplifying

1. Whats the period of the graph of y = 2cos^2 5X -1

period = 2pie/b. I cannot define what the b is. In theory it should be 5, but the power has taken its effect.


2. For y= 5sinXcosX +1, find its amplitude,period, and its range, and its X intercepts X = all real numbers

no idea how to start.^^;

3. simplify sin^2 X + sec^2 X + tan^2 X + cos^2 X
a.2
b. 1+sin^2X/cos^2X
c.2sec^2X
d.2tan^2X

here is what i have done, first finding the common denominator.

= sin^2 X + 1 + Sin^2X + cos^2X
/ cos^2X cos^2X

= (sin^2X)(Cos^2X)+1+Sin^2X+(cos^2X)(cos^2X)
/ cos^2X

then i got stuck..

2.

Use the double angle identity for sine:

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You should be able to go from here...