Please help me on this one i need it

Monica has been saving her spare change. So far she has saved 40 coins for a total of $6.25. Some of the coins are quarters (25

neonofarm [45]

Answer:

10 quarters

40 dimes

Step-by-step explanation:

q + d = 40

25q + 10d = 625

25 > 10

q < d

25(10) = 250

10(40) = 400

$2.50 + $4.00 = $6.00

7 0

3 years ago

For f(x)=4sin(x2) between x=0 and x=3, find the coordinates of all intercepts, critical points, and inflection points to two dec

telo118 [61]

Answer:

Intercepts:

x = 0, y = 0

x = 1.77, y = 0

x = 2.51, y = 0

Critical points:

x = 1.25, y = 4

x = 2.17 , y = -4

x = 2.8, y = 4

Inflection points:

x = 0.81, y = 2.44

x = 1.81, y = -0.54

x = 2.52, y = 0.27

Step-by-step explanation:

We can find the intercept by setting f(x) = 0

$4sin(x^2) = 0$

$sin(x^2) = 0$

$x^2 = n\pi$ where n = 0, 1, 2,3, 4, 5,...

$x = \sqrt(n\pi)$

Since we are restricting x between 0 and 3 we can stop at n = 2

So the function f(x) intercepts at y = 0 and x:

x = 0

x = 1.77

x = 2.51

The critical points occur at the first derivative = 0

$f^{'}(x) = 4cos(x^2)2x = 8xcos(x^2) = 0$

$xcos(x^2) = 0$

$x = 0$ or

$cos(x^2) = 0$

$x^2 = \frac{\pi}{2} + n\pi$ where n = 0, 1, 2, 3

$x = \sqrt{\pi(n+1/2)}$

Since we are restricting x between 0 and 3 we can stop at n = 2

So our critical points are at

x = 1.25, $y = f(1.25) = 4sin(1.25^2) = 4$

x = 2.17 , $y = f(2.17) = 4sin(2.17^2) = -4$

x = 2.8, $y = f(2.8) = 4sin(2.8^2) = 4$

For the inflection point, we can take the 2nd derivative and set it to 0

$f^[''}(x) = 8(cos(x^2) - xsin(x^2)2x) = 8cos(x^2) - 16x^2sin(x^2) = 0$

$cos(x^2) = 2x^2sin(x^2)$

$tan(x^2) = \frac{1}{2x^2}$

We can solve this numerically to get the inflection points are at

x = 0.81, $y = f(0.81) = 4sin(0.81^2) = 2.44$

x = 1.81, $y = f(1.81) = 4sin(1.81^2) = -0.54$

x = 2.52, $y = f(2.52) = 4sin(2.52^2) = 0.27$

3 0

3 years ago

(a) Find the perimeter of the shape below. (Take π = 22/7) 3cm 3cm 12cm 20cm

MariettaO [177]

Try 20cm

it’s correct

3 0

3 years ago

The fifth grade teachers took their classes on a field trip to museum first group had 25 students and two teachers and cost $97.

iren [92.7K]

Answer:

Step-by-step explanation:

S=student cost; T=teacher cost

.

32S+3T=$127 . Multiply this by 2.

64S+6T=$254 Subtract this below

.

25S+2T=$97.50 . Multiply this by 3.

75S+6T=$292.50

64S+6T=$254 . Subtract this (from above.)

.

11S=$38.50

S=$3.50

ANSWER 1: Student tickets cost $3.50.

.

32S+3T=$127

32($3.50)+3T=$127

$112+3T=$127

3T=$15

T=$5.00

ANSWER 2: Teacher tickets cost $5.00.

.

CHECK:

25S+2T=$97.50

25($3.50)+2($5.00)=$97.50

$87.50+$10.00=$97.50

$97.50=$97.50

4 0

3 years ago

30 points can somebody please help me question below

Inessa05 [86]

Find the total number of dogs by adding each day:

Total dogs = 23

Percent of dogs: Divide the number of dogs by the total number of patients:

= 23 / 50 = 0.46 x 100 = 46%

Use the given formula to find the standard error:

Standard error = √(0.46*(1-0.46)/50) = 0.07

90%: Find Z value for 90% ( 1.645) multiply by SE:

1.645 x 0.07 = 0.115 = 0.12

Now add and subtract that value from the Percent from above:

46 + 12 = 58%

46-12 = 34%

Answer (34%, 58%)

95%: Find Z value for 95% ( 1.96) multiply by SE:

1.96 x 0.07 = 0.137 = 0.14

Now add and subtract that value from the Percent from above:

46 + 14 = 60%

46-14 = 32%

Answer (32%, 60%)

5 0

3 years ago