Author Topic: quick qst trig eqns (Read 1249 times) Tweet Share

lacoste · « **on:** May 14, 2009, 04:54:03 pm »

If 0 < x < 10pi, then the number of solutions to the equation sin x = 0 is ?

Flaming_Arrow · « **Reply #1 on:** May 14, 2009, 04:54:56 pm »

pi,2i,3pi.... etc.

lacoste · « **Reply #2 on:** May 14, 2009, 04:58:41 pm »

okay so nine solutions, can someone explain what sin(x)=0 mean?
having a really bad day..... cant think straight

TrueTears · « **Reply #3 on:** May 14, 2009, 05:00:27 pm »

It's when the you sub in a x value you get the y value as 0

Flaming_Arrow · « **Reply #4 on:** May 14, 2009, 05:02:34 pm »

look at where sin is 0 on the unit circle, you can see its at sin(0) and sin(pi)

lacoste · « **Reply #5 on:** May 14, 2009, 05:12:08 pm »

ahhh okay thanks.

what is the number of solutions of cos x = 0 ? | 0 < x < 10pi

thanks!!!

Flaming_Arrow · « **Reply #6 on:** May 14, 2009, 05:16:36 pm »

pi/2,3pi/2,5pi/2 etc

lacoste · « **Reply #7 on:** May 14, 2009, 05:21:08 pm »

how did you get the next value from 3pi/2 .... ?

Flaming_Arrow · « **Reply #8 on:** May 14, 2009, 05:30:41 pm »

add 2pie because its the period

/0 · « **Reply #9 on:** May 15, 2009, 01:20:22 am »

oh dear cos(x) is having its period again -.-
at least it's not as bad as tan(x)

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