All Solutions
Page 583: Practice Problems
$$
begin{align*}
frac{1}{d_{text{o}}} + frac{1}{d_{text{i}}} = frac{1}{f}
end{align*}
$$
where $d_{text{o}}$ is the object distance from the mirror, $d_{text{i}}$ is the image distance, and $f$ is the focal length of the mirror.
We note here that the image is formed behind the mirror, so $d_{text{o}}$ is negative.
$$
begin{align*}
frac{1}{f} &= frac{1}{5.9;text{cm}} + frac{1}{-3.7;text{cm}} \ f &= boxed{-9.9;text{cm}}
end{align*}
$$
$$
begin{align*}
frac{1}{d_{text{o}}} + frac{1}{d_{text{i}}} = frac{1}{f}
end{align*}
$$
where $d_{text{o}}$ is the object distance from the mirror, $d_{text{i}}$ is the image distance, and $f$ is the focal length of the mirror.
We note here that the image is formed behind the mirror, so $d_{text{o}}$ is negative.
$$
begin{align*}
frac{1}{d_{text{o}}} = frac{1}{f} – frac{1}{d_{text{i}}}
end{align*}
$$
$$
begin{align*}
frac{1}{d_{text{o}}} &= frac{1}{-9.6;text{cm}} – left( frac{1}{-4.5;text{cm}} right) \ d_{text{o}} &= boxed{8.5;text{cm}}
end{align*}
$$