hey my name is kerri i'm a college students and i was wondering if you could help in with this problems
sin2x-5sinx-3=0
Hi Kerri,
A great deal of algebra has to do with "pattern recognition". It's like hearing the first chord in a song and knowing who is doing it, even if you have never heard that cut before. no one else makes that sound!
When you show me
sin2x-5sinx-3=0
I see a trinomial
(something)2 - 5 (the same something) - 3 = 0
To do it in a more formal way, let y = sinx then your equation is
y2 - 5 y - 3 = 0
Solve for y. (This doesn't factor so you will have to use te general quadratic.) You will get two possible values for y, a and b. Now you have
sinx = a and sinx = b
Since a and b are sine values they must be between -1 and 1. One of them is not and thus you are left with
sinx = a
What is x?
Penny