f(x, y) = 7(x^5)(y^4) − 9(x^3)(y^8)

Now what i have done is below which i dont think is right for the question of row vector. Could someone help?

(35*x^4*y^4 - 27*x^2*y^8)i + (28*x^5*y^3 - 72*x^3*y^7)j

2. Actually its fine, i found out what to do. thanks anyway

3. Hello,

Originally Posted by taurus
f(x, y) = 7(x^5)(y^4) − 9(x^3)(y^8)

Now what i have done is below which i dont think is right for the question of row vector. Could someone help?

(35*x^4*y^4 - 27*x^2*y^8)i + (28*x^5*y^3 - 72*x^3*y^7)j
Your result is correct, but you're asked a row vector, which will be :

$\overrightarrow{grad}(f)=\left(35x^4y^4-27x^2y^8 \ , \ 28x^5y^3-72x^3y^7\right)$