A plane leaves an airport traveling at 400 mph in the direction N 45° E. A wind is blowing at 40 mph in the direction N 45° W. What is the ground speed of the plane? 400 mph
402 mph
429 mph
440 mph

402 mph

Step-by-step explanation:

Draw a right triangle with 400 and 40 as the two legs.

You know this is a right angle because 45 degrees NE is perpendicular to 45 degrees NW. (imagine a compass)

So, the two side lengths are 400 and 40

Using the Pythagorean theorem, (a^2 + b^2 = c^2) you can see that the answer is 401.995, or 402

B

Step-by-step explanation:

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204