4.Write an Octave script to generate x-values ranging from -3 to 3 with 150 data samples. Define four different y-values using the following equations:

y1 = sin(0.5x) y2 = exp(-0.1x) * cos(3x) y3 = x^3 / (3pi^3) y4 = 0.8 * tanh(0.5*x)

Plot these four curves on the same graph with varying line styles and colors. Include appropriate labels for the x-axis and y-axis, a title for the plot, and a legend.