What you need to know...
Most parents are busy. You work hard all day, juggling professional obligations, family concerns, social commitments, and maybe even some time for yourselves when you can. Often, when you ask about your teenager's day at school, you hear, "Fine." As a result, parents, students and teachers often communicate through grades. What you need to know is that a grade is a lagging indicator of student progress. A student's grade in October is not a reflection of what they are doing in October; it is a sign of what they did in September. Why this is important to bring up is that direct tutoring will move grades upward, but it will not be instantaneous. I have never failed to help a student make progress if the student remains committed to the process and I hope to help your student as well.
"Sounds reasonable. How long until we see results?"
Ideally, you will see some results immediately. In the first handful of weeks, I have generally been able to help a student clarify their work and build confidence. Clarifying comes in two parts: there are technical adjustments to improve accuracy on tasks (e.g. simplifying a function or drawing a graph) and there are improvements in ways of looking at problems, especially the word problems your student probably loves so well. Building confidence is a process of understanding their strengths and and weaknesses so they can accentuate what they're good at and turn the corner on what they're not. With the first several weeks of successful appointments completed, your student should be building habits of mind that will guide them to more independent success. As they develop those assets, their assessment scores and overall course grades will improve.
"Does my student need a lot of technology or will it help?"
Technology is not the magic bullet. Since 2012, I have worked at what is regarded as one of the more accomplished public schools in the city and you would be surprised how little technology we use in our upper-level math courses. My goal is to help your student understand the fundamental relationships that underpin the topics they're studying. Technology will mostly be used as a tool to check work, not to complete it.
"Can you provide a guarantee?"
There are precious few guarantees in direct tutoring. What I can promise is that your student will be able to see math in a more accessible way and be better able to express what they understand. With more tools at their disposal, they may even come to see math as something enjoyable(!). Your student's grade in class relies too much on the individual classroom teacher and her or his methods and practices to give rock solid assurances about grades, though I've always had success in the past.