Final Written Assessment

A cumulative multiple-choice final spanning weeks 1–8: algebra and notation, functions, linear algebra, calculus, optimization, and NumPy shape-reasoning. A mix of calculation, interpretation, and shape questions.

  1. 1.

    For a,b>0a,b>0, which logarithm identity is correct?

  2. 2.

    Evaluate the sum i=132i\sum_{i=1}^{3} 2i.

  3. 3.

    What is the domain of f(x)=ln(x1)f(x)=\ln(x-1)?

  4. 4.

    The sigmoid σ(x)=11+ex\sigma(x)=\frac{1}{1+e^{-x}} has range:

  5. 5.

    Compute the dot product (1,2,3)(4,5,6)(1,2,3)\cdot(4,5,6).

  6. 6.

    Two nonzero vectors are orthogonal. Their cosine similarity is:

  7. 7.

    If AA is 4×34\times 3 and BB is 3×53\times 5, what is the shape of ABAB?

  8. 8.

    The system Ax=bAx=b with AR3×3A\in\mathbb{R}^{3\times 3} has infinitely many solutions when:

  9. 9.

    A covariance matrix has eigenvalues λ1=9, λ2=1\lambda_1=9,\ \lambda_2=1. Keeping the top principal component retains what fraction of the variance?

  10. 10.

    limx0x2+3xx\displaystyle\lim_{x\to 0}\frac{x^2+3x}{x} equals:

  11. 11.

    Differentiate f(x)=3x4f(x)=3x^4.

  12. 12.

    For f(x,y)=3x+y2f(x,y)=3x+y^2, the gradient f\nabla f is:

  13. 13.

    Gradient descent updates the parameters by:

  14. 14.

    In NumPy, adding an array of shape (3,1)(3,1) to one of shape (1,4)(1,4) broadcasts to what shape?