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 !
100 is the answer (100x 2 = 200)
Answer:
x = 17
Step-by-step explanation:
The sum of all angle measures in any triangle is 180 degrees.
- Thus, 23 + 5x - 18 + 90 = 180.
Step 1: Simplify both sides of the equation.
Step 2: Subtract 95 from both sides.
Step 3: Divide both sides by 5.
Step 4: Check if solution is correct.
Thus, x = 17.
Answer:
2
Step-by-step explanation:
2x^2 + 8x + 8
factor the 2 out : 2(x^2 + 4x + 4)
2(x + 2)^2
x = -2
the coordinates of point f is B)7,-5