n
y
=
−
x
−
4
To find the x-intercept, substitute in
0
for
y
and solve for
x
.
0
=
−
x
−
4
Solve the equa
−
x
−
4
=
0
.
−
x
−
4
=
0
Add
4
to both sides of the equation.
−
x
=
4
Multiply each term in
x
=
−
4
by
−
1
x
=
−
4
To find the y-intercept, substitute in
0
for
x
and solve for
y
.
y
=
−
(
0
)
−
4
Simplify
−
(
0
)
−
4
.
Multiply
−
1
by
0
.
y
=
0
−
4
Subtract
4
from
0
.
y
=
−
4
These are the
x
and
y
intercepts of the equation
y
=
−
x
−
4
.
x-intercept:
(
−
4
,
0
)
y-intercept:
(
0
,
−
4
)
not too sure
Answer: cos(x)
Step-by-step explanation:
We have
sin ( x + y ) = sin(x)*cos(y) + cos(x)*sin(y) (1) and
cos ( x + y ) = cos(x)*cos(y) - sin(x)*sin(y) (2)
From eq. (1)
if x = y
sin ( x + x ) = sin(x)*cos(x) + cos(x)*sin(x) ⇒ sin(2x) = 2sin(x)cos(x)
From eq. 2
If x = y
cos ( x + x ) = cos(x)*cos(x) - sin(x)*sin(x) ⇒ cos²(x) - sin²(x)
cos (2x) = cos²(x) - sin²(x)
Hence:The expression:
cos(2x) cos(x) + sin(2x) sin(x) (3)
Subtition of sin(2x) and cos(2x) in eq. 3
[cos²(x)-sin²(x)]*cos(x) + [(2sen(x)cos(x)]*sin(x)
and operating
cos³(x) - sin²(x)cos(x) + 2sin²(x)cos(x) = cos³(x) + sin²(x)cos(x)
cos (x) [ cos²(x) + sin²(x) ] = cos(x)
since cos²(x) + sin²(x) = 1
X= tennis balls Noah has
x<8
