Use a graphing calculator to approximate the real zeros. Give each zero as a decimal to the nearest tenth.
-$$f ( x ) = x ^ { 4 } - 9 x ^ { 2 } + 20$$
A) $- 1,2.7,2.7 , - 2.7$
B) $2.2 , - 2.2,2 , - 2$
C) $2.2,2$
D) $5 , - 5,4 , - 4$

Question

Quizplus · Accepted Answer

The real zeros of the function $f(x) = x^4 - 9x^2 + 20$ can be found by setting the function equal to zero and solving for $x$. This can be done using a graphing calculator by plotting the function and identifying the x-values where the graph crosses the x-axis. The correct zeros, to the nearest tenth, are $2.2, -2.2, 2, -2$, which matches option B.

Use a Graphing Calculator to Approximate the Real Zeros f(x)=x4−9x2+20f ( x ) = x ^ { 4 } - 9 x ^ { 2 } + 20f(x)=x4−9x2+20

Use a Graphing Calculator to Approximate the Real Zeros $f ( x ) = x ^ { 4 } - 9 x ^ { 2 } + 20$