## Lukecrayonz 2 years ago Find all solutions in the interval [0, 2π). sec^2 x - 2 = tan^2 x HELP! :o

1. Lukecrayonz

I'm pretty sure the answer is no solution..

there is no solution... maybe, the typo there

3. ChmE

$\sec^2 x - 2 = \tan^2 x$$\sec^2 x - 1 = \tan^2 x +1$$\sec^2x=\tan^2x+1$$\sec^2x-1=\sec^2x$$-1 \not= 0$No Solution

4. Lukecrayonz

okay thank you so much! can you help me with one more question? @ChmE

5. ChmE

sure

6. Lukecrayonz

A high-altitude spherical weather balloon expands as it rises due to the drop in atmospheric pressure. Suppose that the radius r increases at the rate of 0.16 inches per second and that r = 38 inches at time t = 0. Determine the equation that models the volume V of the balloon at time t and find the volume when t = 280 seconds.

7. ChmE

btw here is a good reference site for these types of problems http://www.sosmath.com/trig/Trig5/trig5/trig5.html

8. ChmE

idk sry. I can't do word problems

9. Lukecrayonz

I have another then! @ChmE

10. Lukecrayonz

Find the inverse of 3√(x/8) -4

11. ChmE

$3\sqrt{{x \over 8} -4}$is this the question

12. Lukecrayonz

yes! the three is the little number

13. Lukecrayonz

@sirm3d help with the inverse question please!

14. sirm3d

starting with x, divide by 8, subtract by 4, take the cube root Inverse: starting with x, cube it, add 4, then multiply by 8

15. sirm3d

it's like socks before shoes. the inverse: shoes before socks

16. sirm3d

the inverse of the function is $\large (x^3+4)(8)$

17. Lukecrayonz

thank you! you're a lifesaver

18. sirm3d

^^