Take a 300dpi photo with an iPhone?

I need to take a 300 dpi photo but i only have an iPhone camera will that work? How to you check the dpi count? It also needs to be 1.5 x 1.75 how do i do this?

Dpi is a printer resolution only. It has nothing to do with the camera.

As Hondo says, DPI is about printing, not cameras nor telephones.

So the photo needs to be 1.5 x 1.75 WHAT? Mm, cm, inches, feet, metres?

Take your photo, then use a program such as Photoshop, Elements, Gimp or paint.net to set the DPI and crop it to the correct dimensions.

You can't change camera DPI. Just take the picture normally then change DPI in the computer. If you don't know how, here's a free tool you can use.

http://keerok-photography.blogspot.com/2012/09/software-for-resizing-changing-dpi-and.html

You only need to set dpi when printing the image. You need post-processing software to modify it if you're printing the image yourself. If you use a professional printer, all that matters are the absolute pixel dimensions. The printer will take care of dpi.