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Given: 3y cos x = x² + y²
Define

Then by implicit differentiation, obtain
3y' cos(x) - 3y sin(x) = 2x + 2y y'
y' [3 cos(x) - 2y] = 2x + 3y sinx)
Answer:
Answer:
(2, -5)
Step-by-step explanation:
x is defined by the first equation as x = -3y – 13. Substitute -3y – 13 for x in the second equation:
2( -3y – 13) + 2y = -6.
Performing the indicated multiplication, we get:
-6y - 26 + 2y = -6
Combining like terms results in:
-4y = 20, so that y = -5
Using the first equation, we find x for y = -5:
x = -3(-5) - 13 = 2
The solution is thus (2, -5) (Answer C)
=7x^4+15x^3+4y^2 I hope this helps!!