Find a function for the graph below. (Graph is in attached file.) It's a multiple choice question and the answers can be:
a. f(t) = 3sin 6t
b. f(t) = 6cos 3t
c. f(t) = -3sin 3t
d. f(t) = 3sin 3t

Question

anonymous · Answer

attachment

anonymous · Answer

c

anonymous · Answer

3 in front of sin changes the amplitude or the magnitude from the usual -1 to + 1 to -3 to +3. The 3 inside the sin() changes the period from the usual 0 to 2pi to 0 to 2pi/3. The minus sign makes a mirror image of sin() in regards of the x axis.

anonymous · Answer

thanks!

anonymous · Answer

http://www.wolframalpha.com/input/?i=plot+-sin%283x%29

anonymous · Answer

http://www.wolframalpha.com/input/?i=plot+-3sin%283x%29 this is your case

anonymous · Answer

normal sin() http://www.wolframalpha.com/input/?i=plot+sin%28x%29 3 times the period http://www.wolframalpha.com/input/?i=plot+sin%283x%29 3 times the period magnitude http://www.wolframalpha.com/input/?i=plot+3sin%283x%29 minus to flip it http://www.wolframalpha.com/input/?i=plot+-3sin%283x%29