ENTS:

I have bought measuring equipment and have been trying to learn how to use it. I am not having any difficulty with the range finder or the clinometer—I think I am getting good data, although I may get better with practice.

The problem is the calculator. I have a Texas Instruments TI-30X IIS. The problem seems to be that I don’t know how to set the calculator so it can do the trig functions as described in Ed Frank’s step-by-step input sequence. When I put in the angle from his example, 47 degrees, and then press the sin button, all I see is the left side of a parenthesis and a flashing upright rectangle, which I assume is like a computer cursor, telling me it is ready for more input rather than presenting me with the sin value. I have experimented with pushing different buttons, but I get nothing.

In the instructions for trig all it says is “enter trig functions (sin, cos, tan, sin -1, cos -1, tan -1), just as you would write them. Set the desired angle mode before starting trig calculations.”

I have done the latter, setting it for degrees.

So, what am I missing here? Do I need a table of the sin values? It seems the calculator is asking me for the sin number. But my understanding is that the calculator should present that to me so I can then multiply that by the distance from my eye to the tree top.

--Gaines