Find the radius when d=18

Mathematics

2 answers:

nirvana33 [79]3 years ago

7 0

Answer:

Step-by-step explanation:

radius is half of the diameter

kherson [118]3 years ago

6 0

Yes 9 is the correct answer

You might be interested in

Let f be the function that determines the area of a circle (in square cm) given the radius of the circle in cm, r. That is, f(r)

yarga [219]

Answer:

The answers to each question are:

a) $A=f(r=4cm)=50.26cm^2$

b) $\Delta A(10.91cm-10.9cm)=f(10.91cm)-f(10.9cm)=0.6851cm^2$

c) $C=5\cdot f(r=12.7cm)=2533.54cm^2$

d) $D=f(r=28cm)+59cm^2=2522.01cm^2$

Step-by-step explanation:

The function f(r) that represents the area of a circle (in square cm) is:

$f(r)=\pi r^2$

a) To represent the area (in square cm) of a circle whose radius is 4 cm, you just have to evaluate the function with a radius of 4cm:

$A=f(r=4cm)=50.26cm^2$

b) To represent how much the area (in square cm) of a circle increases by when its radius increases from 10.9 to 10.91 cm, you have to represent the difference between the final area with a radius of 10.91cm and the initial area of a radius of 10.9cm:

$\Delta A(10.91cm-10.9cm)=f(10.91cm)-f(10.9cm)=0.6851cm^2$

c) To represent the area of 5 circles that all have a radius of 12.7 cm, we can use the function f(r) to represent the area of a circle with a radius of 12.7cm and multiply it for 5:

$C=5\cdot f(r=12.7cm)=2533.54cm^2$

d) To represent the area of the larger circle that is 59 square cm more than the first circle (with a radius of 28 cm), we can use the function f(r) to obtain the area of the first circle and addition 59 square cm:

$D=f(r=28cm)+59cm^2=2522.01cm^2$

6 0

3 years ago

What is the image of (-7, -9) after a reflection over the x-axis?

miss Akunina [59]

Answer:

(-7,9)

Step-by-step explanation:

When you flip over the x-axis, the y-value changes its sign. Vice versa.

4 0

3 years ago

Read 2 more answers