Can anyone give me a hand with this

Pls will give brainliest and all p.s u can zoom in if u cant see plss

Which of the following vectors are orthogonal to (2,1)? check all that apply

Nellie is analyzing a quadratic function f(x) and a linear function g(x). will they intersect? f(x) g(x) graph of the function f of x equals one half times x squared, plus 2 x g(x) 1 5 2 10 3 15