Given the functionf(x)=−5x2−x+20f(x) = −5x^2 − x + 20f(x)=−5x2−x+20, findf(3)f(3)f(3).

Step 1: Define the Problem

We need to evaluate the function $f(x) = -5x^2 - x + 20$ at $x = 3$.

Step 2: Break Down the Problem

Substitute $x = 3$ into the function and simplify to find $f(3)$.

Step 3: Apply Relevant Concepts

Use basic algebraic substitution and arithmetic operations to solve for $f(3)$.

Step 4: Analysis, Verify and Summarize

Substitute and calculate: $f(3) = -5(3)^2 - 3 + 20$ $= -5 \times 9 - 3 + 20$ $= -45 - 3 + 20$ $= -48 + 20$ $= -28$

Final Answer

The value of $f(3)$ is $-28$.