15. Simplify sin(90° - O) cos 0 - sin(180° +0) sin e.

 cos²(θ) + sin(θ)sin(e)

Step-by-step explanation:

sin (90° - θ)cos(Ф) - sin(180° + θ) sin(e)

Note the following identities:

sin (90° - θ) = cos(x)

sin (180° + θ) = -sin(x)

Substitute those identities into the expression:

   cos(x)cos(x)  -  -sin(x)sin(e)

=  cos²(x) + sin(x)sin(e)

step-by-step explanation:

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %