Some advanced precalculus questions

[heyangel]

I got a bunch of homework. But these are the hardest. Others I could have some clues to solve, but for these I'm clueless. Please help

1) If f(x)=3sin x+4sin(x-3) what is the amplitude and period (p) of f(x)?
A) a= 1.114, p = 6.283
B) a= 1.114, p = 3.141
C) a =2.28, p= 3.141
D) a=7, p = 6.283
E) a= 7, p= 9.425

2)A Ferris wheel rider's height above the ground is given by the function h(t)= 20+18 cos [ (pi/4)* (t-3)], where h is measured in feet and t in seconds. How much time is required for the Ferris wheel to complete 1 full revolution?
A) 3 secs
B) 8 secs
C) 18 secs
D) 20 secs
E) 38 secs

3) The graph of the daily temperature at noon of a city is modeled by T= -25 cos [ (2pi/365) * (t-30)] +70, where T represents the temperature in degrees Fareinheit and t represents the day of 365- day year. Whats the range of the temperature from low to high during the year?
A) 25-> 70 Celsius
B) 30-95 Celsius
c) 45-95 Celsius
D) 30-90 Celsius
E) 35-95 Celsius

4) If f(x)= sin x* sin (-x), then which is the range of f(x)?
A) [0,1]
B) [-1,0]
C) [-1,1]
D) [-1,0)
E) (0,1]

5) Function D (t) = (4t)/ (0.01t square+5.1). Given the concentration, D, of a drug in bloodstream where D is measured in micrograms per milliliter and t is minutes from the time the drug is taken. What's the maximum concentration of the drug found in bloodstream at any time?
A) 0.01 micrograms/ milliliters
B) 4 micrograms/ milliliters
C) 5.1 micrograms/ milliliters
D) 8.856 micrograms/ milliliters
E) 22.583 micrograms/ milliliters

 

[tkhunny]

1-1) Period of y = sin(x) and y = sin(x-3) are the same. Why would it change if you add them? It might, but check it out.
1-2) Since you managed to show no work at all, I'll just lay it out there. You tell me how to find it. $\displaystyle \sqrt{24\cdot\cos(3)+25}$

 

[mmm4444bot]

Please do not post lists of exercises with no statements about where you're stuck or what you've tried.

These exercises involve basic concepts -- like "period", "amplitude", "odd function", "range".

Have you learned yet about these concepts? Have you tried looking at graphs of the given functions?

If you show some effort, and ask specific questions of your own, we can determine where to begin helping you.

Also, please check out the post titled, "Read Before Posting". Thanks.