Error when plotting a graph.

[deanhystad]

_x is a numpy array. _y is a single number. Do you want to evaluate m_val*x_val+c_val for each value in _x?

import numpy as np
import matplotlib.pyplot as plt

slope = 2
offset = 3
x = np.linspace(-5,5,100)
y = x * slope + offset
plt.plot(x, y)
plt.show()

Another thing. This makes no sense:

x_val = int(Ex.get()) #x_val stands for x value & is used in calculations

x_val is a range, not a single value. You should have the user enter the range for x, not a single value.