y^2 = x isn't a function because there is at least one value of x that produces multiple values of y. In fact, any x value greater than 0 yields two y values. If x = 0, then y = 0 is the only solution. ... Graphically, the equation fails the vertical line test, which is another way to determine that it is not a function.
I can’t understand why everyone complicates this question. It can be easily solved by similar triangles.
In this png, we have something to make sure.
∠B=∠DAB
∠
B
=
∠
D
A
B
(Yes, dab)
This also means AD=BD
A
D
=
B
D
.
This is our basic construction of D, which is going to help us.
∠ADC=∠DAB+∠B=2∠B=∠CAB
∠
A
D
C
=
∠
D
A
B
+
∠
B
=
2
∠
B
=
∠
C
A
B
∠CAD=∠CAB−∠DAB=∠B
∠
C
A
D
=
∠
C
A
B
−
∠
D
A
B
=
∠
B
These are based on the fact that ∠A=2×∠B
∠
A
=
2
×
∠
B
Actually these conditions suffice. Because I am just proving that △ACD∼△BCA
△
A
C
D
∼
△
B
C
A
Similarity makes us realize the following:
ACBC=ADAB
A
C
B
C
=
A
D
A
B
and
ACBC=CDAC
A
C
B
C
=
C
D
A
C
So
AC×AB=BC×AD
A
C
×
A
B
=
B
C
×
A
D
and
AC2=BC×CD
A
C
2
=
B
C
×
C
D
So
BC2=BC×(BD+CD)=BC×(AD+CD)
B
C
2
=
B
C
×
(
B
D
+
C
D
)
=
B
C
×
(
A
D
+
C
D
)
=AC×AB+AC2
=
A
C
×
A
B
+
A
C
2
Q.E.D.
2.4k Views ·
P = perimeter = 2L + 2W = 86 cm. Also, L = W + 4. Subst. W + 4 for L,
P = 2(W + 4) + 2W = 86 cm. Then 2W + 8 + 2W = 86 cm, and 4W = 78 cm.
Finally solving for W, W = (78 cm)/4, or 19.5 cm.
If W = 19.5 cm, then L = W + 4 cm = 19.5 cm + 4 cm = 23.5 cm
The rectangle's dimensions are 19.5 cm by 23.5 cm.
Whatever% of anything is just (whatever/100) * anything.
now, we know Trever makes $500 in salary and 2% on sales, let's say he sells "x" amount, how much is 2% of x? well (2/100) * x, or 0.02x.
Therefore Trever's earnings are 500 + 0.02x, his salary plus his commission.
to earn a total of 2,000, then 500 + 0.02x = 2000, thus
