Answer:
dy/dx = -b/a cot α
Step-by-step explanation:
x² / a² + y² / b² = 1
Take derivative with respect to x.
2x / a² + 2y / b² dy/dx = 0
2y / b² dy/dx = -2x / a²
dy/dx = -b²x / (a²y)
Substitute:
dy/dx = -b²a cos α / (a²b sin α)
dy/dx = -b cos α / (a sin α)
dy/dx = -b/a cot α
Answer: 40
Step-by-step explanation: It is going up by a constant of 9, so 31 + 9 = 40.
Percent error = 175/225 * 100 = 77.77% = 78% after rounding-off