Answer:
A
Step-by-step explanation:
49y² - x² ← is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , then
49y² - x²
= (7y)² - x²
= (7y - x )(7y + x) → A
Answer:
-42, -21, -14, -7, -6, -3, -2, -1, 1, 2, 3, 6, 7, 14, 21, & 42
Step-by-step explanation:
Cheryl can travel 133.92 miles using 6.2 gallons of gas
This is my answer. Hope that it will help you.
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 !
