Trig Functions are not one-to-one. However, we can restrict the domains to make them one-to-one. The graphs in red show the restricted domains. Note these domains on your chart.
Criteria for choosing a domain:1. The angles should include 0* to 90* (degrees) because they are the measures of the acute angles of a triangle.2. On the restricted domain, the function should take on all the values of the range, that is, all real numbers between –1 and 1.3. The function should be continuous on the restricted domain.
Using your knowledge of inverses, graph the inverse trig functions.
When do we use inverse trig? We use the invere Trig Function when we know what the Sine, Cosine, or Tangent value, but we do not know the angle measure.