Insert pdf image in latex

Question

When I try to insert image like this

\fancypagestyle{mystyle}
{
\setlength{\headheight}{15pt}
\lhead{} \chead{} \rhead{\includegraphics[scale=0.05,trim ={0.25mm 0.25mm 0.25mm 0.25mm},clip=true]{mylogo.pdf}}
\lfoot{} \cfoot{\thepage} \rfoot{}
\renewcommand{\headrulewidth}{0.35 pt}
\renewcommand{\footrulewidth}{0 pt}
}
\pagestyle{mystyle}

it just wont work, and I

\usepackage{graphicx}

I just got logo.pdf text on that place and small little rectangle

I have this

%%HEADER
\fancypagestyle{mystil}
{
\setlength{\headheight}{15pt}
\lhead{} \chead{} \rhead{\includegraphics[scale=0.05,trim ={0.25mm 0.25mm 0.25mm 0.25mm},clip=true]{logo.pdf}}
\lfoot{} \cfoot{\thepage} \rfoot{}
\renewcommand{\headrulewidth}{0.35 pt}
\renewcommand{\footrulewidth}{0 pt}
}
\pagestyle{mystil}

and this on new page

\newpage
\pagestyle{mystil}

Answer 1

This MWE here:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage{fancyhdr}
\usepackage{lipsum}
\fancypagestyle{mystyle}
{
\setlength{\headheight}{15pt}
\lhead{} \chead{} \rhead{\includegraphics[scale=0.05,trim ={0.25mm 0.25mm 0.25mm 0.25mm},clip=true]{example-image}}
\lfoot{} \cfoot{\thepage} \rfoot{}
\renewcommand{\headrulewidth}{0.35 pt}
\renewcommand{\footrulewidth}{0 pt}
}
\pagestyle{mystyle}
\begin{document}
\lipsum
\end{document}

works as expected:

See why preparing a fully working minimal working example (MWE) is so important?

Probably in the process of preparing it, you will be able to find the error --- it happened a lot of times to me. And without it, we can't guess the origin of the problem.