= 1455
generate a few terms of the sequence using
= 3n + 2
= ( 3 × 1) + 2 = 5
= (3 × 2) + 2 = 8
= (3 × 3 ) + 2 = 11
= (3 × 4 ) + 2 = 14
= ( 3 × 5 ) + 2 = 17
the terms are 5, 8, 11, 14, 17
these are the terms of an arithmetic sequence
sum to n terms is calculated using
=
[ 2a + (n-1)d]
where a is the first term and d the common difference
d = 8 - 5 = 11 - 8 = 14 - 11 = 3 and
= 5
=
[( 2 × 5) + (29 × 3) ]
= 15( 10 + 87) = 15 × 97 = 1455
Answer:
No
Step-by-step explanation:
n₁=4
n₂=9
n₃=16
We can see that all three numbers are perfect squares of one higher than the figure number
So, n₁₅=(15+1)²=16₂=256
256≠225
Yes the answer is 24 cm2
because the width is 4 cm then 2 width = 2(4) = 8 cm
perimeter = 20 cm
20-8=12 cm
so 12 cm left is 2 length then the length is 12/2= 6;cm
that's why the area is 4*6= 24 cm2
Answer:
this is a ratio 5:6
Step-by-step explanation: lets say there are 5 apples and 6 pears the ratio would be 5:6
You must develop a cost function C(x) and then minimize its value.
How much dwill the glass cost? It's $1 per sq ft, and the total area of the glass is 4(xh), where x is the length of one side of the base and h is the height of the tank. The area of the metal bottom is x^2, which we must multiply by $1.50 per sq ft.
This cost function will look like this: C(x) = 4($1/ft^2)xh + ($1.50/ft^2)x^2
but we know that (x^2)h= 6 cu ft, or h = (6 cu ft) / (x^2). Subst. this last result into the C(x) equation, immediately above:
C(x) = 4($1/ft^2)x[6 ft^3 / x^2] + ($1.50/ft^2)x^2
Let's focus on the numerical values and ditch the units of measurement for now:
C(x) = 4x(4/x^2) + 1.50x^2, or
C(x) = 16/x + 1.5x^2
Differentiate this with respect to x:
C '(x) = -16 / x^2 + 3 x
Set this equal to 0 and solve for x: -16/x^2 = -3x, or 16 = 3x^3
Then x^3 = 16/3, and x = 5 1/3 ft. We already have the formula
(x^2)h= 6 cu ft, so if x = 5 1/3, or 16/3, then (16/3)^2 h = 6, or
h = 6 / [16/3]^2.
h = 6 (9/256) = 0.21 ft. While possible, this h = 0.21 ft seems quite unlikely.
Please work through this problem yourself, making sure you understand each step. If questions arise, or if you find an error in my approach, please let me know.
Once again:
1. Write a formula for the total cost of the material used: 4 sides of dimensions xh each, plus 1 bottom, of dimensions x^2. Include the unit prices: $1 per square foot for the sides and $1.50 per square foot for the bottom.
2. Differentiate C(x) with respect to x.
3. Set C '(x) = 0 and solve for the critical value(s).
4. Calculate h from your value for x.
5. Write the dimensions of the tank: bottom: x^2; height: h