Let R² have the Euclidean inner product. Find the cosine of the angle between u and v. u=(4,-1) and v= (5,6). Carry out all calculations exactly and round the final answer to 4 decimal places. cos 8 = i

Use a calculator to find the angle between the planes 8x - 9y +6z = -3 and -9x - 5y +5z = -2 to the nearest thousandth of a radian. O 1.551 rad O 0.303 rad O 1.538 rad O 0.019 rad