Chapter 5 Flashcards
Strategies for simplifying using trig identities?
1) Look for a common factor
2) Recognize the pythagorean identities
3) Rewrite everything in terms of sin and cosin
4) when needed, find a common denominator
What are the trig identities
sin^2 + cos^2 = 1
1 + tan ^2 = sec^2
1 + cot^2 = csc^2
Difference of squares-
sec^2 x - 1 creates what when factored
two binomials that are conjugates
Verify Rules
Don’t touch the right side, transform left into the right
what do you do with a quadratic trinomial?
2 sin^2x -sin x -1 =0
Lopezian method
Solving simple trig equations steps
1) If there are common factors collect all trig functions on one side then factor or combine
2) if there are no common factors, use the appropriate ID to convert to a single trig function.
sinku and cosku what do you do? 2sin3t-1=0
you let theta = 3t, or the k
Find the EXACT VALUE. cos 75 degrees
Use sum and difference formulas. for example: cos(30+45) then use that formula cos (u + v)
both angles must be on unit circle!
Solve a MULTIPLE ANGLE EQUATION
for example: 2cosx + sin2x
sin2u formula, plug it in, factor and solve. Tells you what quadrant you can find it in as well
Half Angle Formulas? for example: find the exact value of sin 105 degrees
105 is half of 210, use sin half angle formula using the new number.