Vector Question

[Melanie1993]

I need help with the following problem,
A Motorboat heads N 15 degrees W to cross a river flowing 7.25 miles due East. The boat travels at a speed necessary to head due North. To the nearest mile per hour how fast is the motorboat traveling?

 

[HallsofIvy]

I need help with the following problem,
A Motorboat heads N 15 degrees W to cross a river flowing 7.25 miles due East. The boat travels at a speed necessary to head due North. To the nearest mile per hour how fast is the motorboat traveling?

Have you drawn a picture? You should see a right triangle with one angle 15 degrees, so other acute angle 90- 15= 75 degrees. The side opposite the 15 degree angle has "length" 7.25 miles (per hour, I presume). You can use trigonometry to find the "length" of the hypotenuse which is the speed of the motorboat.