brazil-enem 2017 Q138

brazil-enem · Other · enem__day2 Trig Graphs & Exact Values
Rays of sunlight are hitting the surface of a lake forming an angle $x$ with its surface, as shown in the figure.
Under certain conditions, one can assume that the light intensity of these rays, on the lake surface, is given approximately by $I(x) = K \cdot \sin(x)$, where $k$ is a constant, and assuming that $x$ is between $0^{\circ}$ and $90^{\circ}$.
When $x = 30^{\circ}$, the light intensity is reduced to what percentage of its maximum value?
(A) $33\%$
(B) $50\%$
(C) $57\%$
(D) $70\%$
(E) $86\%$
Rays of sunlight are hitting the surface of a lake forming an angle $x$ with its surface, as shown in the figure.

Under certain conditions, one can assume that the light intensity of these rays, on the lake surface, is given approximately by $I(x) = K \cdot \sin(x)$, where $k$ is a constant, and assuming that $x$ is between $0^{\circ}$ and $90^{\circ}$.

When $x = 30^{\circ}$, the light intensity is reduced to what percentage of its maximum value?\\
(A) $33\%$\\
(B) $50\%$\\
(C) $57\%$\\
(D) $70\%$\\
(E) $86\%$