When you evaluate at 4, you get the square root of 3, so this is going to be 2 times the square root of 3. Then you get 2 times the square root of 4. 5 minus 1 is 4. 2 times the square root of 4 is just 4. Then finally, you get f of 6 is square root of 6 minus 1 is the square root of 5. I think we are now ready to evaluate. Let me get my handy TI-85 out and calculate this.