Let <span>sin(90° - )------------------------ > sin (90-x)
</span>sin(a - b<span>) = sin a*cos b - cos a*sin b
</span><span>so
</span>sin(90 - x) = sin 90*cos x - cos 90 * sin x
sin(90 - x) = 1*cos x - 0* sin x-------- > cos x
the answer is the option <span>D. cos()</span><span>
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125 percent you divide 10 by 8 and get 1.25 then moved the decimal point to the right two spots
You mean "completing the square," don't you? ;)
<span>(x+7)(x-9)=25 can be expanded: x^2 - 9x + 7x - 63 + 25, which becomes
x^2 -2x = 38.
Let's now complete the square:
x^2 - 2x + (1)^2 - (1)^2 = 38, or x^2 - 2x + 1 = 39
Rewrite that as (x-1)^2 = 39
Take the sqrt of both sides: x-1 = plus or minus sqrt(39)
Write the roots: x = 1+sqrt(39) and x = 1 = sqrt(39) (answers)</span>
