Support
Need help, found a bug, or want something added? Email support@dpseven.com. Please say which iPhone, iPad or Mac you are using, which version of iOS, iPadOS or macOS, and, if something gave a wrong answer, the exact expression you typed. That last detail is usually enough to reproduce and fix it the same day.
Before you email: the question everyone asks first
Can I use this in my IB exam?
No. No phone or tablet is permitted in an IB examination. This app is built for homework, revision and checking your work, and it is designed so that what you practise carries over to the graphing calculator you are allowed to take in. The Formula reference & GDC keys page, on Home, lists the keystroke sequences for the approved handheld calculators for sixteen common operations, so you can practise the same operation on the hardware. Tools that no approved calculator can perform are badged Study only, and the computer algebra system is switched off by default for the same reason.
Common questions
Why is my answer only showing three significant figures?
Three significant figures is the IB reporting convention, so it is the
default. Settings will take anything from 1 to 12. Note that intermediate values
are never rounded (rounding happens only when a result is displayed), and exact
integers are shown in full, so 2^10 is 1024 rather than 1020.
Why did 1/2x give a different answer than I expected?
The app reads implicit multiplication as binding more tightly than an
explicit division sign, so 1/2x means 1/(2x). This
matches the Casio convention and the way the expression appears in the formula
booklet. Some other calculators read it as (1/2)x. The two
approved handhelds disagree with each other here. When it matters,
bracket it.
Some tools are missing from the menus.
The course filter in Settings (AA SL, AA HL, AI SL, AI HL) hides everything outside the syllabus you picked, and filters the formula reference to match. Choose Show all to see everything.
How do I turn the computer algebra system on?
Settings, then CAS. It is off by default behind an explanation screen, and while it is on an orange banner sits above every tab. That banner is not a bug and cannot be dismissed: approved exam calculators deliberately exclude a CAS, and it should be obvious when you are relying on one.
Is my work saved? Is it sent anywhere?
It is saved automatically on your device, and it is sent nowhere. The app makes no network requests of its own and collects nothing. The only things that leave it are the ones you tap: the rating prompt, the share sheet and the support email link. See the privacy policy. The calculator works fully in Airplane Mode.
How do I type a fraction, a root, or an integral?
Use the structure keys on the keypad. The editor is two-dimensional:
fractions stack, roots take a vinculum, and integrals carry their limits.
Pressing a structure key captures what you just typed: type 2 then
the power key and 2 becomes the base. Backspace walks the structure rather than
deleting characters blindly, so from the start of a denominator it moves to the
end of the numerator. On a hardware keyboard, typing a slash builds a real
fraction.
An unclosed bracket still evaluated.
That is intended. sin(30 evaluates as sin(30),
which is what a handheld calculator does when you press EXE. A surplus
closing bracket is still reported as an error, because that one is a genuine
slip.
Things the app deliberately does not do
- General implicit relations typed directly, such as x² + y² = 25, are handled through the Conic sections tool rather than a general implicit plotter.
- Symbolic integration refuses rather than guesses. If it cannot find an antiderivative it says so. For checking your own work, a refusal is more useful than a confident wrong answer.
- Multi-step undo is not available. Undo goes back one step, like the handheld; ink on a Scribble page is the exception. History is kept, and any earlier result can be tapped to reuse.
- Programs cannot be imported. The built-in programming language runs only what you type into the app.
Reporting a wrong answer
A wrong answer is the most serious bug the app can have. If you find one, send the exact expression, what the app returned, and what you expected. If a markscheme or your teacher disagrees with the app, say so. A few conventions in the app are deliberate judgement calls between two defensible readings, so tell us which one your school teaches.
Contact
Email support@dpseven.com for help, bug reports or feature requests.