Confused on how to solve this question and am stuck.

[Stormynight]

Hi everyone, I’m stuck on question 17c and am confused on how to find x. So far all I’ve got is that 20 - x = the square root of 64 + x squared. Any help would be appreciated, thanks!

 

[topsquark]

View attachment 34289
Hi everyone, I’m stuck on question 17c and am confused on how to find x. So far all I’ve got is that 20 - x = the square root of 64 + x squared. Any help would be appreciated, thanks!
View attachment 34290

Hint: Square both sides.

-Dan

 

[Deleted member 4993]

Hi, I did that but now I’m not sure what to do with the other side. The answers supposed to be 8.4 km by the way. Thanks for the previous feedback!View attachment 34302

Your work does not show "squaring both sides". It should be"

20 - x = \(\displaystyle \sqrt{64 - x^2}\)

Squaring both sides:

\(\displaystyle (20 - x)^2 = (\sqrt{64 - x^2})^2\)

400 - 40*x + x^2 = 64 - x^2 ..............................continue

 

[Stormynight]

Ok thank you so much! I was quite confused

 

[Harry_the_cat]

Your work does not show "squaring both sides". It should be"

20 - x = \(\displaystyle \sqrt{64 - x^2}\)

Squaring both sides:

\(\displaystyle (20 - x)^2 = (\sqrt{64 - x^2})^2\)

400 - 40*x + x^2 = 64 - x^2 ..............................continue

should be + x^2 at end.

 

[topsquark]

should be + x^2 at end.

From where?

-Dan

 

[Dr.Peterson]

should be + x^2 at end.

You mean,

[imath]20 - x = \sqrt{64 {\color{red}+} x^2}[/imath]​

right?

 

[Steven G]

Your work does not show "squaring both sides". It should be"

20 - x = \(\displaystyle \sqrt{64 - x^2}\)

Squaring both sides:

\(\displaystyle (20 - x)^2 = (\sqrt{64 - x^2})^2\)

400 - 40*x + x^2 = 64 - x^2 ..............................continue

Corner time!

 

[Harry_the_cat]

You mean,

[imath]20 - x = \sqrt{64 {\color{red}+} x^2}[/imath]​

right?

Yes which will make it +x^2 at the end.

 

[Deleted member 4993]

Corner time!

- I am already there for previous infraction....