The answer to your question is C.
        
             
        
        
        
Answer:
62.50 or 0.625
Step-by-step explanation:
 
        
             
        
        
        
Let's work on the left side first. And remember that 
the<u> tangent</u> is the same as <u>sin/cos</u>.
sin(a) cos(a) tan(a)
Substitute for the tangent:
[ sin(a) cos(a) ] [ sin(a)/cos(a) ] 
Cancel the cos(a) from the top and bottom, and you're left with
[ sin(a) ] . . . . . [ sin(a) ] which is [ <u>sin²(a)</u> ]  That's the <u>left side</u>.
Now, work on the right side:
[ 1 - cos(a) ] [ 1 + cos(a) ]
Multiply that all out, using FOIL:
[ 1 + cos(a) - cos(a) - cos²(a) ]
= [ <u>1 - cos²(a)</u> ] That's the <u>right side</u>.
Do you remember that for any angle, sin²(b) + cos²(b) = 1  ?
Subtract cos²(b) from each side, and you have sin²(b) = 1 - cos²(b) for any angle.
So, on the <u>right side</u>, you could write [ <u>sin²(a)</u> ] .
Now look back about 9 lines, and compare that to the result we got for the <u>left side</u> . 
They look quite similar. In fact, they're identical. And so the identity is proven.
Whew !
        
                    
             
        
        
        
Answer:I think it might be c
Step-by-step explanation:
 
        
             
        
        
        
Answer:
Carla has been running 7 miles each day for 13 days.
Step-by-step explanation:
Carla ran 3 miles on her first day, 5 miles on her second day and then 7 miles each day onward.
Let the number of days she ran 7 miles each day = x
Total distance run by Carla = 3 + 5 + 7(x)
                                              = 8 + 7x
If her log book shows that she has run total distance = 99 miles
Equation representing her total run will be,
8 + 7x = 99
7x = 99 - 8
7x = 91
x = 
x = 13 days
Therefore, Carla has been running 7 miles each day for 13 days.