Let f be a function of two variables that has continuous partial derivatives and consider the points A(3, 5), B(7, 5), C(3, 7), and D(11, 20). The directional derivative of f at A in the direction of the vector $\vec{AB}$ is 4 and the directional derivative at A in the direction of $\vec{AC}$ is 22. Find the directional derivative of f at A in the direction of the vector $\vec{AD}$. (Round the answer to two decimal places.)

i have no idea just need points sorry

step-by-step explanation:

1. 180°. the sum of the interior angles of a triangle is 180°, for the equilateral triangle that it has three equals side is 60°+60°+60°=180°.

2. 60°. each interior angle of a equilateral triangle is 60°

3. 120°. the measure of ∠m is 120°, the sum of the angles ∠m and ∠n is equal to 180°. so, in order to find the measure of ∠m, we have ∠m+∠n=180° > ∠m=180°-∠n > ∠m=180°-60°=120°.

4. 360°. the sum of the exterior angles of an equilateral triangle is ∠m+∠r+∠x=120°+120°+120°=360°. the exterior angles of any triangle always add 360°.

whats the rest of it?