Which of the following expressions is not equal to the others?
A. cos 35º cos 37° - sin 35° sin 37°
B. cos 100° cos 28° + sin 100° sin 28°
C. cos 72°
D. COS 100° cos 28° - sin 100° sin 28°

the anser is B

Step-by-step explanation:cos  cos 35º cos 37° - sin 35° sin 37°°- COS 100° cos 28° - sin 100° sin 28°- cos 72°= cos 100° cos 28° + sin 100° sin 28°

14

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204