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:
47.32 kilometers per hour
Step-by-step explanation:
194 (kilometers) / 4.1 ( hours)
194/4.1 = 47.32 kilometers per hour.
The diameter of the plate is 12, and the formula for finding circumference is diameter times pie. so you multiply pie (or 3.14 if you aren't using a calculator) times 12 and it should give you 37.6991. rounded to the nearest tenth, that's 37.7, hope I helped!
I don't understand what you want solved for here...could you please tell me?
4/3 • 5/3 = 20/9 divided by 2 = 10/9