2x^2+ 3x+ 1= (2x+1)(x+1)<br />
Complete the square in the square root: 2x^2+ 3x+ 1= 2(x^2+ (3/2)x+ 9/16)+1-9/8= 2(x+ 3/2)^2- 1/8. Let u= x+ 3/2, then du= dx and x= u- 3/2 so that 2x+ 4= 2u+ 1 so the function to be integrated becomes (2u+1)(2u^2+ 7/16)^{1/2}= 2\sqrt{2}u(u^2+ 7/32)^{1/2}+ \sqrt{2}(u^2+ 7/32}^{1/2}. The first can be integrated by the substitution v= u^2+ 7/32 and the second by a trig substitution.
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#3
Anony111
4
0
I get the idea but you have made one mistake; it should be 9/8 instead of 9/16 outside the bracket. Thanks a lot though