A = (1/2) * b * h
The base is 10; the x-value going from 0 to 10.
The perpendicular height is 2; the y-value going from 0 to 2
A = (1/2) * 10 * 2
A = 10 units ^2
<span>( 7 x - 11 )
<span>( 7 - 5x )</span></span>
You do the implcit differentation, then solve for y' and check where this is defined.
In your case: Differentiate implicitly: 2xy + x²y' - y² - x*2yy' = 0
Solve for y': y'(x²-2xy) +2xy - y² = 0
y' = (2xy-y²) / (x²-2xy)
Check where defined: y' is not defined if the denominator becomes zero, i.e.
x² - 2xy = 0 x(x - 2y) = 0
This has formal solutions x=0 and y=x/2. Now we check whether these values are possible for the initially given definition of y:
0^2*y - 0*y^2 =? 4 0 =? 4
This is impossible, hence the function is not defined for 0, and we can disregard this.
x^2*(x/2) - x(x/2)^2 =? 4 x^3/2 - x^3/4 = 4 x^3/4 = 4 x^3=16 x^3 = 16 x = cubicroot(16)
This is a possible value for y, so we have a point where y is defined, but not y'.
The solution to all of it is hence D - { cubicroot(16) }, where D is the domain of y (which nobody has asked for in this example :-).
(Actually, the check whether 0 is in D is superfluous: If you write as solution D - { 0, cubicroot(16) }, this is also correct - only it so happens that 0 is not in D, so the set difference cannot take it out of there ...).
If someone asks for that D, you have to solve the definition for y and find that domain - I don't know of any [general] way to find the domain without solving for the explicit function).
Answer:
There were 3 adults
Step-by-step explanation:
Step 1: Derive the first expression
a+c=10...equation 1
where;
a=number of adults
c=number of children
And total number of people=10
Step 2: Derive the second expression;
Total cost of tickets=(price per child ticket×number of children)+(price per adult ticket×number of adults)
where;
Total cost of tickets=$186.50
price per child ticket=$15.95
price per adult ticket=$24.95
number of children=c
number of adults=a
replacing;
(15.95×c)+(24.95×a)=186.5
24.95 a+15.95 c=186.5....equation 2
Step 3: Combine equation 1 and 2 and solve simultaneously
24.95 a+15.95 c=186.5
-
24.95(a+c=10)
(24.95 a-24.95 a)+(15.95 c-24.95 c)=186.5-(24.95×10)
-9 c=-63
c=-63/-9
c=7
replace the value for c in equation 1
a+c=10
a+7=10
a=10-7
a=3
There were 3 adults