The student didn't make any mistake. The slope of the line between those points is 3/8.
Answer:
55/54
Step-by-step explanation:
Answer:
-2
Step-by-step explanation:
Answer:
See below.
Step-by-step explanation:
1. (1 / 2)[cos(a – b) – cos(a + b)]
= 1/2 ( cosa cosb + sina sinb - (cosa cosb - sina sinb)
= 1/2 ( cosa cosb - cosa cos b + sina sinb + sina sinb)
= 1/2 ( 2 sina sinb)
= sina sinb.
(I used the 2 identities cos(a - b) = cosa cosb + sina sinb) and
cos (a + b) = cosa cosb - sina sinb.)
2. sin (π/2 - x) = sin (π/2) cos x - cos(π/2) sin x
= 1 * cos x - 0 * sinx
= cosx - 0
= cos x.
(I used the identity sin(a - b) = sina cosb - cosa sinb
and the fact that sin(π/2) = 1 and cos (π/2) = 0. )
