Answer:
(a)Therefore the value of x=
(b) Therefore the value of x 
Step-by-step explanation:
Horizontal tangent line: The first order derivative of a function gives the slope of the tangent of the function. The slope of horizontal line is zero.If the slope of tangent line is zero then the tangent line is called horizontal tangent line.
(a)
Given function is,

Differential with respect to x

For horizontal tangent line, f'(x)=0
3+ 3 cos x= 0
⇒3 cos x=-3
⇒cos x=-1
⇒x = 180° 
Therefore the value of x=
(b)
Given that, the slope is 3.
Then,f'(x)=3
3+ 3 cos x= 3
⇒3 cos x= 3-3
⇒cos x=0
⇒x = 90° 
Therefore the value of x 
30(-2/5)²(5/8) = 30*(4/25)*(5/8) = 30*4/(5*8) = 3
He circumference of a circle<span> is equal to the diameter times pi. So, let's look at </span>what happens<span> if you double the </span>radius<span> of a </span>circle<span> -- say from 2 to 4. The area will go from 12.56 to 50.24. This means that it has </span>quadrupled<span>.</span>
Answer:
he drove 43.25 miles per hour
Step-by-step explanation:
you have to divided miles by hours so 346/8= 43.25mph
H has two lines of symmetry
Going vertical and horizontal.
Hope that helped!