Pleasee help mee

12sin(x)-5cos(x)=6,5

We turn -5,12 into polar coordinates.  It's a Pythagorean Triple so

r = 13   Ф=arctan(-12/5) + 180°   ( in the second quadrant )

so -5 = 13 cos Ф, 12 = 13 sin Ф

12 sin x - 5 cos x = 6.5

13 sinФ sin x + 13 cos Ф cos x = 6.5  

13 cos(x - Ф) = 6.5

cos(x - Ф) = 1/2

cos(x - Ф) = cos 60°

x - Ф = ± 60° + 360° k     integer k

x = Ф ± 60° + 360° k  

x = 180° + arctan(-12/5) ± 60° + 360° k  

That's the exact answer;

x ≈  180° - 67.38° ± 60° + 360° k  

x ≈  122.62° ± 60° + 360° k  

x ≈  { 62.62°, 182.62°} + 360° k,  integer k

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.