Step-by-step explanation:
You have to do first and second derivatives :
y = a sin 3x + b cos 3x
dy/dx = 3a cos 3x - 3b sin 3x
d²y/dx² = - 9a sin 3x - 9b cos 3x
Next, you have to compare it :
let d²y/dx² = ky,
-9a sin 3x - 9b cos 3x = k(a sin 3x + b cos 3x)
-9(a sin 3x + b cos 3x) = k(a sin 3x + b cos 3x)
Therefore, k is equals to 9.
The answer would be 3n^2 + 2.
This can be found/proven by replacing "n" with term number (1,2,3,4...), then solving to get the final number. For example 3 * 1^2 + 2. You would first do 1^2, which is 1. Next, you would multiply 1 by 3, to get 3. Finally, you'd and the 2 to get 5. 5 is the 1st term, and you can use this same equation to get the rest of the terms you need.
I hope this helps!
Answer:
a = 85° , b = 30° , c = 65°
Step-by-step explanation:
∠ a and 85° are alternate angles and are congruent , so
a = 85°
∠ c and 65° are alternate angles and are congruent , so
c = 65°
a, b and c lie on a straight line and sum to 180° , that is
a + b + c = 180°
85° + b + 65° = 180°
150° + b = 180° ( subtract 150° from both sides )
b = 30°
