Answer:cos( A + B ) = cosAcosB - sinAsinB ;
cos( A + B ) / ( cosAsinB ) = ( cosAcosB - sinAsinB ) / ( cosAsinB ) = ( cosAcosB ) / ( cosAsinB ) - ( sinAsinB ) / ( cosAsinB ) = cosB / sinB - sinA / cosA = cotB - tanA ;
tan²(x) - sin²(x) = sin²(x)/cos²(x) - sin²(x)
… = sin²(x) (1/cos²(x) - 1)
… = sin²(x) (sec²(x) - 1)
… = sin²(x) tan²(x)
Step-by-step explanation:
Answer:
x = -19
Step-by-step explanation:
x-9/-4=7
x-9= -28
x= -28+ 9
x = -19
Answer:

Step-by-step explanation:
The equation of a parabola in vertex form:

<em>(h, k)</em><em> - vertex</em>
The focus is

We have the vertex (2, -5) and the focus (2, -4).
Calculate the value of <em>a</em> using 
<em>k = -5</em>
<em>add 5 to both sides</em>
<em>multiply both sides by 4</em>


Substitute

to the vertex form of an equation of a parabola:

The standard form:

Convert using


<em>use the distributive property: a(b+c)=ab+ac</em>

Answer:
Nonlinear
Step-by-step explanation:
This is nonlinear because its parent function is y =
. The parent function of a linear equation is y = x.
I hope this helps :))
Answer:

Step-by-step explanation:
start by foiling out the given function

next, use the power rule to find the derivative
power rule: To use the power rule, multiply the variable's exponent n, by its coefficient a, then subtract 1 from the exponent. If there's no coefficient (the coefficient is 1), then the exponent will become the new coefficient.
